ASME B18.31.1M Metric Continuous-Thread Studs (Double-End, Full Body)

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 B18.31.1M Metric Continuous-Thread Studs (Double-End, Full Body)) 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.

Continuous-thread or double-end stud — how do the two tables differ in practice?

By where the thread needs to be. The continuous-thread stud (Table 1) is threaded over its whole length — the choice for through-studs with nuts both ends, where position along the length is adjusted with the nuts. The double-end stud (Table 2) carries a defined tap end BM that screws into a tapped flange or housing, a plain or reduced body in the middle, and a nut end; the collected table dimensions the tap end separately per diameter (2.1-2.7 mm at M1.6 up to 148-152 at M100) because engagement in the tapped hole is a controlled fit, not a leftover. The length-band columns also differ — continuous studs key off total stud length LT, double-ends off nominal length L — and in both tables the B min/max pairs widen with the band: longer stud, proportionally longer thread per end. Order by configuration, diameter and pitch together ("M12 x 1.75 double-end x 60"), and name which end is the tap end.

What does U max = 2P mean at the thread runout?

It is the allowance for the incomplete thread where the rolled or cut thread dies out — at most two pitches of it. At M12 (pitch 1.75) that is up to 3.5 mm of partial thread per end; at M100 (pitch 6), 12 mm. The figure matters in two real situations: a stud screwed to the bottom of a blind tapped hole, where the runout must not be counted as engagement (the full-thread length B min already excludes it — that is why the tables give min/max), and a nut run-up, where the last two pitches may not carry full form. Read the U column as the boundary between "threaded" and "almost threaded" and neither gauge the stud nor set the nut against the runout itself.