{"product_id":"bhtzp20275h","title":"Hexagon Head Bolts - Zinc Plated, Hi - Tensile - (grade 8.8), DIN 931, M20 X 275 mm","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eDIN 931 defines a hexagon head bolt with a partially threaded shank. The standard covers the dimensional form of the bolt, including the hex head, threaded portion and plain shank, so that the fastener can be selected consistently by diameter, length and thread. The partially threaded design is useful where the smooth shank should pass through the joint to improve alignment and carry shear loads, while the threaded section provides the clamping force.\u003c\/p\u003e\u003cp\u003eThis selected size is specified with diameter M20, length 275 mm, thread M20, pitch 2.5 mm.\u003c\/p\u003e\u003cp\u003eSold in multiples of '1 pieces. 1 Box = '1 pieces.\u003c\/p\u003e\u003ch3\u003eMaterial, Grade \u0026amp; Strength\u003c\/h3\u003e\u003cp\u003eGrade 8.8 is a high tensile carbon-alloy steel property class commonly used for structural and mechanical bolting. The “8.8” designation indicates a nominal ultimate tensile strength of approximately 800 MPa and a yield strength of approximately 80% of that value, about 640 MPa. This makes it substantially stronger than ordinary mild steel fasteners and suitable for general engineering joints where higher clamp load and shear resistance are required. For critical assemblies, torque must be selected from a recognised torque chart using the actual thread size, pitch, lubrication condition, surface finish and mating nut grade. Use compatible high tensile nuts and washers rather than low-strength mild steel mating parts.\u003c\/p\u003e\u003ch3\u003eFinish \u0026amp; Corrosion Protection\u003c\/h3\u003e\u003cp\u003eZinc plating provides a sacrificial protective coating for indoor and general industrial environments. Yellow passivation can improve corrosion resistance and gives the familiar yellow\/gold appearance.\u003c\/p\u003e\u003ch3\u003eTypical Uses\u003c\/h3\u003e\u003cp\u003eDIN 931 bolts are commonly used in machinery, fabricated steelwork, mining equipment, agricultural equipment, brackets, frames and maintenance work where a strong partially threaded bolt is preferred over a fully threaded set screw.\u003c\/p\u003e\u003ch3\u003eTechnical Tips\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eUse a matching nut and washer of the same thread size and suitable strength class.\u003c\/li\u003e\n\u003cli\u003eWhere possible, position the plain shank through the shear plane of the joint rather than leaving threads in the shear area.\u003c\/li\u003e\n\u003cli\u003eFor Grade 8.8, 10.9 or 12.9 bolts, use correctly rated mating nuts and washers.\u003c\/li\u003e\n\u003cli\u003eTorque values vary by diameter, pitch, finish and lubrication; always confirm the correct torque before use in safety-critical assemblies.\u003c\/li\u003e\n\u003cli\u003eFor corrosion-sensitive applications, match the finish or material to the environment rather than relying only on strength grade.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSelection Advice\u003c\/h3\u003e\u003cp\u003eChoose DIN 931 when the joint benefits from a partially threaded shank. Choose DIN 933 when a fully threaded hexagon head set screw is required. Confirm diameter, length, thread, material, finish and grade before ordering.\u003c\/p\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat is the difference between DIN 931 and DIN 933?\u003c\/strong\u003e DIN 931 is partially threaded, while DIN 933 is fully threaded. DIN 931 is often preferred where the plain shank assists alignment or shear performance.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs Grade 8.8 stainless steel?\u003c\/strong\u003e No. Grade 8.8 normally refers to high tensile carbon-alloy steel. Stainless fasteners are usually specified by A2, A4 or a stainless property class.\u003c\/p\u003e","brand":"Screwman","offers":[{"title":"Default Title","offer_id":49604475322608,"sku":"BHTZP20275H","price":115.0,"currency_code":"ZAR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0833\/4875\/0576\/files\/931_Z.jpg?v=1781382755","url":"https:\/\/screwman.co.za\/products\/bhtzp20275h","provider":"Screwman","version":"1.0","type":"link"}