Precision Fasteners
Engineered to Global Standards
Longze Engineering supplies precision bolts, screws, nuts and washers — manufactured and verified against DIN, ISO and ASME standards for demanding industrial applications.
Product Range
Complete fastener families — from metric hex bolts to imperial socket cap screws, with full size coverage.
Hex Bolts & Screws
DIN 933/931, ISO 4017/4014 — fully and partially threaded hexagon head bolts in metric sizes from M1.6 to M64.
Socket Cap Screws
DIN 912 / ISO 4762 internal hex socket head cap screws with precise thread control for high-strength assemblies.
Nuts
DIN 934 / ISO 4032 hexagon nuts matching our bolt range for reliable mating pairs.
Washers
DIN 125-A / ISO 7089 flat washers, DIN 127-A spring washers, DIN 7980 — full load-spreading support.
Imperial & ASME
ASME B18.2.1 hex bolts, B18.2.2 square/hex nuts, B18.21.1 washers, B18.3 socket screws — inch sizes.
Surfaces & Strength
Surface treatments (Zn, HDG, DACROMET, phosphate) and mechanical property grades from 4.6 to 12.9.
Standards & Engineering
Every product is documented against its governing standard — geometry, materials, finishes and equivalence, with engineering-grade detail pages.
Standards Library
Browse full standard interpretations with dimensional data, size matrices and equivalence mapping.
Engineering Center
Structured engineering knowledge — equivalence clusters, specification pages and industry guidance.
Surface Treatment
Zn, Zn-Yellow, HDG, DACROMET, phosphate, black oxide, nickel, chrome — with selection guidance.
Mechanical Properties
Property classes 4.6 – 12.9, 100–300 HV — tensile, yield and hardness data per grade.
Need a Quote?
Tell us your standard, size and quantity — we respond with engineering-supported pricing.
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