Standardisation of screw thread forms is an ongoing process begun in the 19th century. Metric The most widely used screw thread standard in use world-wide today is ISO metric ('M' for short) threads. This thread standard was introduced in 1947 by the International Organisation for Standardisation and since then has been steadily supplanting the use of other metric and inch based thread standards in use around the world.اقرأ أكثر
Standard: ASTM A325/Din933 hex bolts Dia.: 1/2""-1 1/2""; Length:1 1/4""-8""; Surface treatment: Plain ,Black oxygenation, HDGاقرأ أكثر
The American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.اقرأ أكثر
The ASTM A153 specification covers zinc coating (hot-dip) on iron and steel hardware. A newer and more appropriate specification developed in 2005 covering the requirement for hot-dip galvanizing of bolts, screws, nuts, washers and other threaded fasteners is ASTM F2329. It is not yet widely used since many of the ASTM specifications covering bolts,اقرأ أكثر
Originally approved in 1936, this specification is heavily utilized in petroleum and chemical construction applications. The ASTM standard covers alloy steel and stainless steel bolting materials for high temperature service. This specification includes fasteners intended for use in pressure vessels, valves, flanges, and fittings.اقرأ أكثر
The ASTM A194 specification covers carbon, alloy and stainless steel nuts intended for use in high-pressure and/or high-temperature service. Unless otherwise specified, the American National Standard Heavy Hex Series (ANSI B 18.2.2) shall be used. Nuts up to and including 1 inch nominal size shall be UNC Series Class 2B fit. Nuts over 1 inch nominal size shall be either UNC Series Class 2B fit or 8اقرأ أكثر
Originally approved in 1948, the ASTM A320 specification covers alloy steel and stainless steel bolting materials for low temperature service. This standard covers rolled, forged, or strain hardened bars, bolts, screws, studs, and stud bolts used for pressure vessels, valves, flanges, and fittings. Like the ASTM A193 specification, unless otherwise specified, the 8UN thread series is specified on fastener larger than 1” in diameter.اقرأ أكثر
