ASME B18.2.4.6M Heavy Hex Nuts (Metric)

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 (ASME B18.2.4.6M Heavy Hex Nuts (Metric)) 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 10,000 pieces. Stock items run 3–7 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.

Which nut goes on a B18.2.6M heavy hex bolt — and can a standard hex nut be substituted?

The heavy nut, B18.2.4.6M, and the substitution is a real derating. The collected table shows what the heavy nut provides: thickness M at roughly the full nominal diameter (12.3 mm at M12, 100 at M100) against visibly less on a standard-thickness nut, and the same across-flats ladder as the heavy bolt head (21 mm at M12), so the assembly turns with one wrench. A standard hex nut threads on and can clamp, but its shorter engagement reduces the shear area carrying the load — the margin high-preload joints size for — and its lighter across-flats means the wrench that tightened the bolt cannot turn the nut without slipping. Match the designations: B18.2.6M or B18.2.3.3M bolt with B18.2.4.6M nut, class paired to class, both named on the RFQ.

Why does the table run to M100 — and what does FIM mean at that size?

Because heavy metric nuts live in industries that build big: heavy equipment, structural towers, large flange systems — where M64 to M100 fasteners are ordered, not improvised. At those sizes the collected table's runout column becomes the quality gate worth asking about: total runout of bearing surface FIM max rises from 0.38 mm at M12 to 2.62 mm at M100, the permitted tilt of the washer face relative to the thread axis. On an M100 nut that face is nearly 150 mm across (Dw min 137.8), so a runout at the limit seats the nut like a slightly wedged washer — the clamp load concentrates on one arc of the face instead of the full annulus. For critical joints, ask for the actual runout on the certificate alongside proof-load test evidence; the geometry table gets you the right part, the certificate gets you the right part verified. Both property class and proof load stay per RFQ — the collected page does not tabulate them.