ISO Metric Hexagon Hardware — Head, Nut and Washer Dimensions

Documents

Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.

Quotation

• The fastener family (ISO Metric Hexagon Hardware — Head, Nut and Washer Dimensions) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
• Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
• Quantity per size and your target delivery date.
• Destination country, and any required documents (for example a mill test certificate) so the quote includes them.

Sample & supply

Minimum order quantity is 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 days. Quantities or variants outside the standard range are confirmed at quotation.

Storage & shipping

Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.

Why does the fine-pitch nut grid repeat the coarse values, and when does that matter?

Because wrench size is driven by the nut diameter across flats, not by the thread. An M20 nut is 30 across flats whether its thread is 2.5 coarse or 2.0 fine — the standard keeps one nut hex for both, so the fine grid exists mainly to pair each fine pitch with the right size and to carry the e min corner and m height per size. The place it matters practically is mixed assemblies: if a drawing mixes a fine-pitch bolt into a coarse-thread nut train, the wrench fits but the threads will not — check pitch pairing on the drawing, not the wrench. For thin or overloaded joints, also verify nut height m against the bolt's thread protrusion requirement; m max is tabulated here per size.

How do I use the washer d1/d2/h tolerances with the bolt and nut grids?

Three checks, one per column pair. d1 (hole) must clear the bolt's nominal diameter with its tolerance band — M12 washer hole 13.00 min clears the 12 mm bolt shank, and the 0.27 max-min band is what stops the washer from binding on the shank corner. d2 (OD) must cover the nut's bearing face: e min at M12 coarse is 20.03, and the M12 washer OD min of 23.48 covers it with margin — that bearing-coverage check is the real reason washer OD grows faster than hole size on the ladder. h (thickness) sets the load spreading; the ladder thickens in steps (0.5 at M3, 2.5 at M12, 4.0 at M24 max) roughly with the bolt's capacity. If your joint needs a wider or thicker bearing face than the ladder gives, that is a heavy-series or structural washer — say so on the RFQ rather than stretching this grid.