{"id":7203,"date":"2024-10-08T14:50:19","date_gmt":"2024-10-08T05:50:19","guid":{"rendered":"https:\/\/yasudaseiki.com\/en-test\/?page_id=7203"},"modified":"2025-10-10T13:30:06","modified_gmt":"2025-10-10T04:30:06","slug":"what-is-dtul","status":"publish","type":"page","link":"https:\/\/yasudaseiki.com\/en-test\/what-is-dtul\/","title":{"rendered":"What is Deflection Temperature Under Load (DTUL)? Vicat Softening Temperature Test and Ball Pressure Test also explained!"},"content":{"rendered":"\n<div class=\"hdt lp-page\">\n    <div class=\"head-text\">\n        <p>The <span class=\"text-bold\">Deflection Temperature Under Load (DTUL)<\/span> test is one of the methods used to measure the heat resistance of plastics. In this test, a specified <span class=\"text-bold\">flexural stress<\/span> is applied to the sample in a three-point bending setup, and the temperature is gradually increased. The temperature at which the <span class=\"text-bold\">deflection under load<\/span> exceeds a certain value is measured. This test is used to evaluate the heat resistance of plastic products, such as microwave-safe plastic dishes, commonly found in daily life.<br>In addition to the DTUL test, other methods for measuring the heat resistance of plastics include the <span class=\"text-bold\">Vicat Softening Temperature (VST)<\/span> test and the <span class=\"text-bold\">Ball Pressure (BP)<\/span> test. This page provides a detailed explanation of each testing method.<\/p>\n    <\/div>\n    \n    <section class=\"hdt-overview lp-section\">\n        <h2 class=\"page-h2\">Overview and Principle of Testing<\/h2>\n        <div class=\"hdt-overview-dtul\">\n            <h3 class=\"page-h3\">DTUL &#8211; Deflection Temperature Under Load Test<\/h3>\n            <p>(Reference Standards: JIS K 7191-1,2,3 \/ ISO 75-1,2,3 \/ ASTM D648)<br>The <span class=\"text-bold\">Deflection Temperature Under Load<\/span> is measured by applying a specified <span class=\"text-bold\">flexural stress<\/span> in a three-point bending setup and gradually increasing the temperature. The test measures the temperature at which the sample reaches a specified deflection amount, known as the Deflection Temperature Under Load.<\/p>\n            <div class=\"image-c-solo inner-contents\">\n                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/148_DTUL_eg-16.09.49.gif\" alt=\"hdt-overview-dtul\">\n            <\/div>\n            <div class=\"hdt-overview-dtul-structure\">\n                <h4 class=\"page-h4\">Structure of the Testing Machine<\/h4>\n                <div class=\"image-c-solo inner-contents lp-image-size-70\">\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/ca702b0223da70893f6566dba2dba6a2.png\" alt=\"hdt-dtul-structure\">\n                    <span class=\"lp-image-subtext\">Example of a Deflection Temperature Under Load Testing Machine<\/span>\n                <\/div>\n                <p class=\"inner-contents\">The basic structure of the testing machine is shown in the diagram above.<br>The load application system consists of a <span class=\"text-bold\">flexural stress load frame<\/span>, thermometer, load shaft, weights, loading edge, and sample supports. The weights are placed on top of the load shaft, and a loading edge is attached to its tip. The sample supports are fixed to the bottom of the frame. Additionally, the heating bath is equipped with a control system that allows the temperature to increase at a constant rate of <span class=\"text-bold\">120\u00b110\u00b0C\/h<\/span>.<\/p>\n            <\/div>\n            <div class=\"hdt-overview-dtul-method\">\n                <h4 class=\"page-h4\">Test Method<\/h4>\n                <div class=\"image-c-solo inner-contents lp-image-size-50\">\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/075d9445096e38f738def08069f46072.png\" alt=\"hdt-dtul-method\">\n                <\/div>\n                <p class=\"inner-contents\">The load is applied to the sample so that the specified <span class=\"text-bold\">flexural stress<\/span> is generated in a three-point bending setup. The stress applied to the sample should meet one of the following conditions:<\/p>\n                <ul class=\"inner-contents\">\n                    <li>\n                        JIS\/ISO Standard\n                        <ul>\n                            <li>Method A: 1.80 MPa (recommended value)<\/li>\n                            <li>Method B: 0.45 MPa<\/li>\n                            <li>Method C: 8.00 MPa<\/li>\n                        <\/ul>\n                    <\/li>\n                    <li>\n                        ASTM Standard\n                        <ul>\n                            <li>0.455 MPa<\/li>\n                            <li>1.82 MPa<\/li>\n                        <\/ul>\n                    <\/li>\n                <\/ul>\n                <p class=\"inner-contents\">The load is calculated using the following formula:<\/p>\n                <div class=\"hdt-overview-dtul-method-calculation\">\n                    <p class=\"lp-sub-title\">\u3010JIS\/ISO Standard\u3011<\/p>\n                    <div class=\"lp-calculation\">\n                        <div class=\"lp-calculation-inner\">\n                            <div>\n                                <span>FW (Flatwise)<\/span>\n                                <div>\n                                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/0ff7f3a85f9be17d3fed55477fad60e6.png\" alt=\"hdt jis\/iso flatwise formula\">\n                                <\/div>\n                            <\/div>\n                            <div>\n                                <span>EW (Edgewise)<\/span>\n                                <div>\n                                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/c57241c1c42f8caf89a3ebf4f9226140.png\" alt=\"hdt jis\/iso edgewise formula\">\n                                <\/div>\n                            <\/div>\n                        <\/div>\n                        <div class=\"lp-calculation-inner lp-calculation-inner-sp-end\">\n                            <div>\n                                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/90ed2ccbc8a65b33302ca7c0ddae8fa6.png\" alt=\"hdt jis\/iso symbol\">\n                            <\/div>\n                        <\/div>\n                    <\/div>\n                    <p class=\"lp-sub-title inner-contents\">\u3010ASTM Standard\u3011<\/p>\n                    <div class=\"lp-calculation\">\n                        <div class=\"lp-calculation-inner\">\n                            <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/6bc5e2e7594d17f89bcd7383ef759230.png\" alt=\"hdt ASTM formula\">\n                        <\/div>\n                        <div class=\"lp-calculation-inner\">\n                            <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/2d16399e1cabae9571bba77a0798bac7.png\" alt=\"hdt ASTM symbol\">\n                        <\/div>\n                    <\/div>\n                <\/div>\n            <\/div>\n            <div class=\"hdt-overview-dtul-method\">\n                <h4 class=\"page-h4\">Measurement Method<\/h4>\n                <p class=\"inner-contents\">Place the sample on the sample supports. The sample is loaded with weights and inserted into the heating bath. The temperature is increased at a constant rate of <span class=\"text-bold\">120\u00b110\u00b0C\/h<\/span>. The temperature at which the sample deflection reaches the specified value <span class=\"text-bold\">(Deflection Temperature Under Load)<\/span> is measured.<\/p>\n                <p class=\"inner-contents\">The standard deflection is calculated using the following formula:<\/p>\n                <p class=\"lp-sub-title inner-contents\">\u3010JIS\/ISO Standard\u3011<\/p>\n                <div class=\"lp-calculation\">\n                    <div class=\"lp-calculation-inner\">\n                        <div>\n                            <span>FW (Flatwise)<\/span>\n                            <div>\n                                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/be0ab0037b889b450ff43827555c0125.png\" alt=\"hdt jis\/iso flatwise formula\">\n                            <\/div>\n                        <\/div>\n                        <div>\n                            <span>EW (Edgewise)<\/span>\n                            <div>\n                                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/a21a749e903acb8a262454dd87028cc6.png\" alt=\"hdt jis\/iso edgewise formula\">\n                            <\/div>\n                        <\/div>\n                    <\/div>\n                    <div class=\"lp-calculation-inner lp-calculation-inner-sp-end\">\n                        <div>\n                            <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/7c7a3035b30a7dd3c8c7227d3406d528.png\" alt=\"hdt jis\/iso symbol\">\n                        <\/div>\n                    <\/div>\n                <\/div>\n                <p class=\"sp-inner-contents\">\u203bFor ASTM, the standard deflection is <span class=\"text-bold\">0.25 mm<\/span>.<\/p>\n            <\/div>\n        <\/div>\n        <div class=\"hdt-overview-dtul\">\n            <h3 class=\"page-h3\">VST &#8211; Vicat Softening Temperature Test<\/h3>\n            <p>(Reference Standards: JIS K 7206 \/ JIS K 6742 \/ JIS K 6816 \/ ISO 306 \/ ISO 1452-1,2 \/ ISO 2507-1 \/ ASTM D1525)<br>The <span class=\"text-bold\">Vicat Softening Temperature (VST)<\/span> is the temperature at which a <span class=\"text-bold\">1.0 mm<\/span> penetration is achieved by the indenter into the surface of the sample under gradually increased temperature while a load is applied. The VST test evaluates the temperature at which thermoplastic materials begin to soften rapidly.<\/p>\n            <div class=\"image-c-solo inner-contents\">\n                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/148_VST_eg-1.gif\" alt=\"hdt-overview-vicat\">\n            <\/div>\n            <p class=\"inner-contents\">The test methods are classified into four types: A-50, A-120, B-50, and B-120, each with specified loads and heating rates (JIS\/ISO).<\/p>\n            <p class=\"s-annotation\">Note: ASTM does not classify test methods like JIS\/ISO, but specifies the same loads and heating rates.<\/p>\n            <div class=\"js-scrollable scroll-hint table-area is-scrollable\">\n                <table class=\"lp-hdt-test-table\">\n                    <thead>\n                        <tr>\n                            <th colspan=\"3\">JIS K7206 \/ISO 306 \/ ASTM D1525<\/th>\n                        <\/tr>\n                    <\/thead>\n                    <tbody>\n                        <tr>\n                            <th>Test Methods (JIS\/ISO Only)<\/th>\n                            <th>Load<\/th>\n                            <th>Heating Rate<\/th>\n                        <\/tr>\n                        <tr>\n                            <td>Method A50<\/td>\n                            <td>10\u00b10.2N<\/td>\n                            <td>50\u2103\/h<\/td>\n                        <\/tr>\n                        <tr>\n                            <td>Method A120<\/td>\n                            <td>10\u00b10.2N<\/td>\n                            <td>120\u2103\/h<\/td>\n                        <\/tr>\n                        <tr>\n                            <td>Method B50<\/td>\n                            <td>50\u00b11N<\/td>\n                            <td>50\u2103\/h<\/td>\n                        <\/tr>\n                        <tr>\n                            <td>Method B120<\/td>\n                            <td>50\u00b11N<\/td>\n                            <td>120\u2103\/h<\/td>\n                        <\/tr>\n                    <\/tbody>\n                <\/table>\n            <\/div>\n        <\/div>\n        <div class=\"hdt-overview-dtul\">\n            <h3 class=\"page-h3\">BP &#8211; Ball Pressure Test<\/h3>\n            <p>(Reference Standard: Electrical Appliances and Materials Safety Act (2014) Appendix Table 3 Method B in the report on &#8220;The registration system for ball pressure temperature of thermoplastics used in electrical appliances and material.\u201d)<\/p>\n            <p class=\"inner-contents\">In this test, a <span class=\"text-bold\">steel ball indenter<\/span> with a 5 mm diameter is used. A load of <span class=\"text-bold\">20+0\/-0.4N<\/span> is applied to the heated sample for one hour, and the temperature at which the indent diameter on the sample surface reaches <span class=\"text-bold\">2 mm<\/span> is measured. <\/p>\n            <p class=\"s-annotation\">Note: IEC 60335-1 and Electrical Appliances and Materials Safety Act (2014) Appendix Table 3 Method A uses a different procedure with a system of weights designed to apply a downward force while placed in an oven, differing from the above test content.<\/p>\n            <div class=\"image-c-solo inner-contents lp-image-size-50\">\n                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/00eb0231633fd48d144ac795f7cef084.png\" alt=\"hdt-BP-test\">\n            <\/div>\n        <\/div>\n    <\/section>\n    <section class=\"hdt-standards lp-section\">\n        <h2 class=\"page-h2\">List of Standards<\/h2>\n        <p>Standards for measuring the heat resistance of plastics exist in both JIS (ISO) and ASTM. Both standards include test methods for <span class=\"text-bold\">DTUL<\/span> and <span class=\"text-bold\">VST<\/span>. The Ball Pressure Test is specified in the Electrical Appliances and Materials Safety Act.<\/p>\n        <div class=\"js-scrollable scroll-hint table-area is-scrollable\">\n            <table class=\"lp-hdt-test-table lp-hdt-standard-table-f\">\n                <thead>\n                    <tr>\n                        <th colspan=\"2\">Standard<\/th>\n                        <th>Year<\/th>\n                        <th>Test Method<\/th>\n                        <th>Standard Name<\/th>\n                    <\/tr>\n                <\/thead>\n                <tbody>\n                    <tr>\n                        <th rowspan=\"5\">JIS<\/th>\n                        <td>K7191-1<\/td>\n                        <td>2015<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics-Determination of temperature of deflection under load- Part 1: General test method<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>K7191-2<\/td>\n                        <td>2015<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics-Determination of temperature of deflection under load- Part 2: Plastics and ebonite<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>K7191-2<\/td>\n                        <td>2007<\/td>\n                        <td>DTUL(EW)<\/td>\n                        <td>Plastics-Determination of temperature of deflection under load- Part 2: Plastics and ebonite AppendixA<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>K7191-3<\/td>\n                        <td>2007<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics-Determination of temperature of deflection under load-Part 3: High-strength thermosetting laminates and long-fibre-reinforced plastics<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>K7206<\/td>\n                        <td>2016<\/td>\n                        <td>VST<\/td>\n                        <td>Plastics-Thermoplastic materials- Determination of Vicat softening temperature (VST)<\/td>\n                    <\/tr>\n                    <tr>\n                        <th rowspan=\"4\">ISO<\/th>\n                        <td>ISO75-1<\/td>\n                        <td>2020<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics \u2014 Determination of temperature of deflection under load\u30fcPart 1: General test method<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>ISO75-2<\/td>\n                        <td>2013<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics \u2014 Determination of temperature of deflection under load \u2014 Part 2: Plastics and ebonite<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>ISO75-3<\/td>\n                        <td>2004<\/td>\n                        <td>DTUL<\/td>\n                        <td>Plastics \u2014 Determination of temperature of deflection under load \u2014 Part 3: High-strength thermosetting laminates and long-fibre-reinforced plastics<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>306<\/td>\n                        <td>2022<\/td>\n                        <td>VST<\/td>\n                        <td>Plastics \u2014 Thermoplastic materials\u2014 Determination of Vicat softening temperature (VST)<\/td>\n                    <\/tr>\n                <\/tbody>\n            <\/table>\n        <\/div>\n        <p class=\"lp-sub-title inner-contents\">PVC Pipe and Plastic Pipe Related Standards<\/p>\n        <div class=\"js-scrollable scroll-hint table-area is-scrollable\">\n            <table class=\"lp-hdt-test-table lp-hdt-standard-table-s\">\n                <thead>\n                    <tr>\n                        <th colspan=\"2\">Standard<\/th>\n                        <th>Year<\/th>\n                        <th>Test Method<\/th>\n                        <th>Standard Name<\/th>\n                    <\/tr>\n                <\/thead>\n                <tbody>\n                    <tr>\n                        <th rowspan=\"2\">JIS<\/th>\n                        <td>K6742<\/td>\n                        <td>2016<\/td>\n                        <td>VST<\/td>\n                        <td>Unplasticized poly(vinyl chloride) (PVC-U) pipes for water supply<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>K6816<\/td>\n                        <td>2008<\/td>\n                        <td>VST<\/td>\n                        <td>Thermoplastics pipes and fittings- Test method for Vicat softening temperature<\/td>\n                    <\/tr>\n                    <tr>\n                        <th rowspan=\"3\">ISO<\/th>\n                        <td>1452-1<\/td>\n                        <td>2009<\/td>\n                        <td>VST<\/td>\n                        <td>Plastics piping systems for water supply and for buried and above-ground drainage and sewerage under pressure \u2014 Unplasticized poly(vinyl chloride) (PVC-U) \u2014 Part 1: General<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>1452-2<\/td>\n                        <td>2009<\/td>\n                        <td>VST<\/td>\n                        <td>Plastics piping systems for water supply and for buried and above-ground drainage and sewerage under pressure \u2014 Unplasticized poly(vinyl chloride) (PVC-U) \u2014 Part 2: Pipes<\/td>\n                    <\/tr>\n                    <tr>\n                        <td>2507-1<\/td>\n                        <td>1955<\/td>\n                        <td>VST<\/td>\n                        <td>Thermoplastics pipes and fittings \u2014 Vicat softening temperature \u2014 Part 1: General test method<\/td>\n                    <\/tr>\n                <\/tbody>\n            <\/table>\n        <\/div>\n    <\/section>\n    <section class=\"hdt-conditions lp-section\">\n        <h2 class=\"page-h2\">Test Conditions<\/h2>\n        <div class=\"hdt-conditions-dtul\">\n            <h3 class=\"page-h3\">DTUL &#8211; Deflection Temperature Under Load Test<\/h3>\n            <div class=\"image-c-solo inner-contents lp-image-size-50\">\n                <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/fa58ec3a3dc1e499b10defed696a3745.png\" alt=\"hdt-dtul-test-conditions\">\n            <\/div>\n            <p class=\"lp-sub-title inner-contents\">Sample Dimensions<\/p>\n            <div class=\"image-c-twin inner-contents\">\n                <div class=\"image-twin-inner\">\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/26158d7120612bf034db757f7cb58de7.png\" alt=\"edgewise\">\n                <\/div>\n                <div class=\"image-twin-inner\">\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/c7cfc8657496d1bbfe40bc9c034e37fe.png\" alt=\"flatwise\">\n                <\/div>\n            <\/div>\n            <div class=\"js-scrollable scroll-hint table-area is-scrollable\">\n                <table class=\"lp-hdt-test-table lp-hdt-dtul-table\">\n                    <thead>\n                        <tr>\n                            <th>Standard<\/th>\n                            <th>JIS K 7191-1,2 \/ISO 75-1,2<\/th>\n                            <th>JIS K 7191-2 (2007) Appendix A\/ ISO 75-2 (2004)<\/th>\n                            <th>JIS K 7191-3 \/ISO 75-3<\/th>\n                            <th>ASTM D648<\/th>\n                        <\/tr>\n                    <\/thead>\n                    <tbody>\n                        <tr>\n                            <th>Test Method<\/th>\n                            <td>DTUL FW<\/td>\n                            <td>DTUL EW<\/td>\n                            <td>DTUL FW<\/td>\n                            <td>DTUL EW<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Sample Dimensions<\/th>\n                            <td>l=80\u58eb2.0mm,<br>b=10\u58eb0.2mm,<br>h=4\u58eb0.2mm<\/td>\n                            <td>l=120\u58eb10mm,<br>b=9.8~15mm,<br>h=3.0~4.2mm<\/td>\n                            <td>l=at least10mm longer than span between supports,<br>b=9.8~12.8mm,<br>h=2.0~7.0mm<\/td>\n                            <td>I=at least 12.7mm longer than span between supports (127mm commonly used),<br>b=12.7\u58eb0.5mm,<br>h=3~13mm<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Span between Supports<\/th>\n                            <td>64\u58eb1mm<\/td>\n                            <td>100\u58eb1mm<\/td>\n                            <td>30h\u00b11mm<\/td>\n                            <td>Method A:<br>101.6\u58eb0.5mm,<br>Method B: 100\u58eb0.5mm<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Loading Edge<\/th>\n                            <td>R3.0\u58eb0.2mm<\/td>\n                            <td>R3.0\u58eb0.2mm<\/td>\n                            <td>R3.0\u58eb0.2mm<\/td>\n                            <td>R3.0\u58eb0.2mm<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Flexural Stress<\/th>\n                            <td>Method A: 1.80MPa<br>Method B: 0.45MPa<br>Method C: 8.00MPa<\/td>\n                            <td>Method A: 1.80MPa<br>Method B: 0.45MPa<br>Method C: 8.00MPa<\/td>\n                            <td>Equivalent to 1\/1000 of the Flexural modulus<\/td>\n                            <td>Method A: 1.82MPa<br>Method B: 0.455MPa<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Temperature Increase Rate<\/th>\n                            <td>120\u58eb10\u00b0C\/h<\/td>\n                            <td>120\u58eb10\u00b0C\/h<\/td>\n                            <td>120\u58eb10\u00b0C\/h<\/td>\n                            <td>2\u58eb0.2\u00b0C\/min<\/td>\n                        <\/tr>\n                    <\/tbody>\n                <\/table>\n            <\/div>\n            <span class=\"s-annotation\">Note: The DTUL EW test specified in JIS K 7191-2(2007) Annex A was deleted in JIS K 7191-2 (2015).<\/span>\n            <p class=\"inner-contents\">According to JIS K 7191-1, sample dimensions and flexural stress are specified by K 7191-2 and K 7191-3; however, tests conducted under the conditions specified in JIS K 7191-2 are generally the most common.<\/p>\n        <\/div>\n        <div class=\"hdt-conditions-vstbp\">\n            <h3 class=\"page-h3\">Vicat Softening Temperature (VST) Tester &#038; Ball Pressure (BP) Test<\/h3>\n            <div class=\"image-c-twin inner-contents\">\n                <div class=\"image-twin-inner\">\n                    <span class=\"image-c-text\">\u3010VST\u3011<\/span>\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/a754657225ff5ed7b3b804e57b929830.png\" alt=\"VST\">\n                <\/div>\n                <div class=\"image-twin-inner\">\n                    <span class=\"image-c-text\">\u3010BP\u3011<\/span>\n                    <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2024\/10\/85b7909f7951338537839549fea7eadd.png\" alt=\"BP\">\n                <\/div>\n            <\/div>\n            <div class=\"js-scrollable scroll-hint table-area is-scrollable\">\n                <table class=\"lp-hdt-test-table lp-hdt-vst-table\">\n                    <thead>\n                        <tr>\n                            <th>Standard<\/th>\n                            <th>JIS K 7206 \/ISO 306<\/th>\n                            <th>JIS K 6816<\/th>\n                            <th>ASTM D1525<\/th>\n                            <th>Electrical Appliances and Materials Safety Act<\/th>\n                        <\/tr>\n                    <\/thead>\n                    <tbody>\n                        <tr>\n                            <th>Test Method<\/th>\n                            <td>VICAT<\/td>\n                            <td>VICAT<\/td>\n                            <td>VICAT<\/td>\n                            <td>BP<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Sample Dimensions<\/th>\n                            <td>Square plate: \u226710mm<sup>\u203b<\/sup> or circular plate: diameter \u226710mm<sup>\u203b<\/sup>, thickness 3-6.5mm<br>\u203bISO306 is \u22679mm<\/td>\n                            <td>Width: 10-20mm, thickness:2.4-6mm, length:tube 50\u00b15mm<\/td>\n                            <td>Square plate: \u226710mm, thickness 3-6.5mm<\/td>\n                            <td>Square plate: \u226715mm, thickness 3\u00b10.5mm<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Indenter<\/th>\n                            <td>Cylinder: 1.5-3mm length, cross-sectional area 1.000\u00b10.015\u339f<\/td>\n                            <td>Cylinder: 3mm length, cross-sectional area 1.000\u00b10.015\u339f<\/td>\n                            <td>Cylinder: 2mm length, cross-sectional area 1.000\u00b10.015\u339f<\/td>\n                            <td>5mm diameter, Grade 40 steel ball<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Load<\/th>\n                            <td>A50\/A120 method: 10\u00b10.2N, B50\/B120 method: 50\u00b11N<\/td>\n                            <td>50\u00b11N<\/td>\n                            <td>10\u00b10.2N, 50\u00b11N<\/td>\n                            <td>20N+0\/-0.4N<\/td>\n                        <\/tr>\n                        <tr>\n                            <th>Temperature Increase Rate<\/th>\n                            <td>120\u00b110\u2103\/h,<br>50\u00b15\u2103\/h<\/td>\n                            <td>50\u00b15\u2103\/h<\/td>\n                            <td>120\u00b110\u2103\/h,<br>50\u00b15\u2103\/h<\/td>\n                            <td>&#8211;<\/td>\n                        <\/tr>\n                    <\/tbody>\n                <\/table>\n            <\/div>\n        <\/div>\n    <\/section>\n    <section class=\"hdt-water-pipe lp-section\">\n        <h2 class=\"page-h2\">Water Pipe Testing (JIS K 6816)<\/h2>\n        <p>Rigid polyvinyl chloride pipes commonly used for water supply are subject to the test items and performance criteria specified in JIS K 6742. The Vicat Softening Temperature (VST) test is one of the test items, and the testing method follows JIS K 6816.<br>Additionally, the Japan Water Works Association&#8217;s &#8220;Inspection Procedure for Water Supply PVC Pipes&#8221; and the AS20 &#8220;Unplasticized poly (vinyl chloride) (PVC-U) pipes for water supply&#8221; from the Japan PVC Pipe and Fittings Association also refer to JIS K 6742 for testing. Let&#8217;s take a closer look at the test methods.<\/p>\n        <div class=\"hdt-water-pipe-overview\">\n            <h3 class=\"page-h3\">Test Overview<\/h3>\n            <p>The basic test method is based on the method B50 of the Vicat Softening Temperature (VST) test, as specified in JIS K 7206. A load of 50\u00b11N is applied to the sample, and the sample is immersed in a heating medium that increases the temperature at a rate of 50\u00b0C\/h. The temperature at which the indenter penetrates 1\u00b10.01mm into the sample, made from water pipes or fittings, is recorded as the Vicat Softening Temperature.<\/p>\n            <span class=\"s-annotation\">Note: Unlike JIS K 7206, the heating medium is preheated to a temperature approximately 50\u00b0C lower than the expected Vicat Softening Temperature and maintained at that level prior to the test.<\/span>\n            <div class=\"js-scrollable scroll-hint table-area is-scrollable\"><\/div>\n                <table class=\"lp-hdt-test-table\">\n                    <thead>\n                        <tr>\n                            <th>Sample Dimensions<\/th>\n                            <th>Loading Edge<\/th>\n                        <\/tr>\n                    <\/thead>\n                    <tbody>\n                        <tr>\n                            <td>Width: 10-20 mm<br>Thickness: 2.4-6 mm<br>Length: Pipe length 50\u00b15 mm, Joint 15-50 mm<\/td>\n                            <td>Indenter size: 3 mm diameter cylindrical shape<br>Cross-sectional area: 1.000\u00b10.015 mm\u00b2<\/td>\n                        <\/tr>\n                    <\/tbody>\n                <\/table>\n            <\/div>\n        <\/div>\n    <\/section>\n    <section class=\"hdt-water-pipe lp-section\">\n        <h2 class=\"page-h2\">Yasuda Seiki\u2019s Testing Machine: No.148 Heat Distortion Tester<\/h2>\n        <p>Our Heat Distortion Tester can perform <span class=\"text-bold\">Deflection Temperature Under Load (DTUL)<\/span> tests, <span class=\"text-bold\">Vicat Softening Temperature (VST)<\/span> tests, and <span class=\"text-bold\">Ball Pressure (BP)<\/span> tests. We also offer customization for existing products. For more details, please refer to the link below.<\/p>\n        <div class=\"lp-yss-tester-3item lp-yss-tester inner-contents\">\n            <div class=\"lp-yss-tester-3item-inner lp-yss-tester-inner\">\n                <a href=\"https:\/\/yasudaseiki.com\/en-test\/product\/plastic_rubber\/heat-desertion\/\">\n                    <div>\n                        <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2025\/10\/148-HD-4-001.png\" alt=\"No.148-HD\">\n                    <\/div>\n                    <p><span class=\"lp-yss-tester-item-title\">No.148-HD<\/span>Compatible with DTUL, VST, and BP tests. Available in both benchtop and floor-standing models.<\/p>\n                <\/a>\n            <\/div>\n            <div class=\"lp-yss-tester-3item-inner lp-yss-tester-inner\">\n                <a href=\"https:\/\/yasudaseiki.com\/en-test\/product\/plastic_rubber\/heat-desertion\/\">\n                    <div>\n                        <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2018\/05\/148-HD500.jpg\" alt=\"No.148-HD500\">\n                    <\/div>\n                    <p><span class=\"lp-yss-tester-item-title\">No.148-HD500<\/span>Capable of testing at ultra-high temperatures (up to 500\u00b0C). Uses highly durable borosilicate glass on the test frame.<\/p>\n                <\/a>\n            <\/div>\n            <div class=\"lp-yss-tester-3item-inner lp-yss-tester-inner\">\n                <a href=\"https:\/\/yasudaseiki.com\/en-test\/product\/plastic_rubber\/heat-desertion\/\">\n                    <div>\n                        <img decoding=\"async\" src=\"https:\/\/yasudaseiki.com\/en-test\/wp-content\/uploads\/2025\/10\/148-HDA.png\" alt=\"No.148-HDA\">\n                    <\/div>\n                    <p><span class=\"lp-yss-tester-item-title\">No.148-HDA<\/span>Fully automates the testing process. By simply entering the test conditions and loading the samples, continuous measurement of up to 120 samples can be performed.<\/p>\n                <\/a>\n            <\/div>\n        <\/div>\n    <\/section>\n    <section class=\"bottom-contact-area lp-section\">\n        <p class=\"bottom-contact-area-title\">Contact Us<\/p>\n        <p class=\"bottom-contact-area-text\">With over 65 years of experience in supporting the quality control and R&#038;D of various industrial fields, Yasuda Seiki consistently aims to satisfy our customers\u2019 various needs.<\/p>\n        <div class=\"bottom-btn\">\n            <a href=\"https:\/\/yasudaseiki.com\/en-test\/contact\/\">Inquiry Form<\/a>\n        <\/div>\n    <\/section>\n    <section class=\"lp-standard-area lp-section\">\n        <p class=\"lp-standard-area-title\">Reference Standards<\/p>\n        <ul>\n            <li>ISO 75-1 (JIS K 7191-1) Plastics \u2014 Determination of temperature of deflection under load\u30fcPart 1: General test method<\/li>\n            <li>ISO 75-2 (JIS K 7191-2) Plastics \u2014 Determination of temperature of deflection under load \u2014 Part 2: Plastics and ebonite<\/li>\n            <li>ISO 75-3 (JIS K 7191-3) Plastics \u2014 Determination of temperature of deflection under load \u2014 Part 3: High-strength thermosetting laminates and long-fibre-reinforced plastics<\/li>\n            <li>ISO 306 (JIS K 7206) Plastics \u2014 Thermoplastic materials\u2014 Determination of Vicat softening temperature (VST)<\/li>\n            <li>Electrical Appliances and Materials Safety Act (2014) Appendix Table 3 Method B in the report on &#8220;The registration system for ball pressure temperature of thermoplastics used in electrical appliances and material.&#8221; <\/li>\n            <li>JIS K 6742 Unplasticized poly(vinyl chloride) (PVC-U) pipes for water supply<\/li>\n            <li>JIS K 6816 Thermoplastics pipes and fittings-Test method for Vicat softening temperature<\/li>\n        <\/ul>\n    <\/section>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The Deflection Temperature Under Load (DTUL) test is one of the methods used to measure the heat resistance of plastics. In this test, a specified flexural stress is applied to the sample in a three-point bending setup, and the temperature is gradually increased. The temperature at which the deflection under load exceeds a certain value [&hellip;]<\/p>\n","protected":false},"author":6,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-7203","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/pages\/7203","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/comments?post=7203"}],"version-history":[{"count":40,"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/pages\/7203\/revisions"}],"predecessor-version":[{"id":8816,"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/pages\/7203\/revisions\/8816"}],"wp:attachment":[{"href":"https:\/\/yasudaseiki.com\/en-test\/wp-json\/wp\/v2\/media?parent=7203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}