Internal-external thread fasteners (double-threaded screws and nuts with both OD and ID threads) cannot be produced by thread rolling due to thin wall sections and non-standard thread profiles. This article...
Read MoreA comprehensive guide to automatic screw machine types: Swiss-type (walking-spindle) vs walking-tool (cam-type) auto lathes, detailed specifications of the 5-tool cam automatic lathe (precision, speed, output), how bowl cams and...
Read MoreRoHS Directive 2002/95/EC Annex Item 6 exempts lead as an alloying element in copper alloys up to 4% by weight. This means C3604 free-cutting brass (Pb 1.8–3.7%) and other leaded...
Read MoreA practical beginner's guide to operating a cam-type automatic screw machine (walking-tool lathe), covering the 3 fundamental learning steps: cutting principles, tool grinding, and machine setup (cam adjustment). Includes machine...
Read MoreStainless steel fastener galling (seizing) is caused by the combination of 304/316's high ductility and poor thermal conductivity, which causes thread surfaces to adhesively weld together under friction and heat....
Read MoreHydrogen embrittlement (HE) is a critical failure mode in high-strength electroplated fasteners, causing sudden brittle fracture at stresses below yield strength. This guide covers the causes and mechanisms of HE...
Read MoreReference tables for bolt and screw breaking torque (failure torque): austenitic stainless steel Grade 50/70/80 (M1.6–M16, per GB/T 3098.6-2000) and carbon steel Grade 8.8/9.8/10.9/12.9 (M1–M10, per GB/T 3098.13), with fine-pitch...
Read MoreStainless steel fasteners (304, 316) being magnetic is a normal result of cold working during manufacturing — not a sign of counterfeit or substandard material. This article explains the austenite-to-martensite...
Read MoreSUS303 is the correct stainless steel for CNC turned parts, not SUS304. This article compares their actual chemical compositions as used in turning bar stock, explains why SUS303's high sulfur...
Read More40Cr is a medium-carbon chromium alloy structural steel (GB/T 3077) offering tensile strength ≥ 800–1000 MPa after quenching and tempering, with significantly better hardenability than plain 45 steel. This guide...
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