ASME B1.10M Unified Miniature Screw Threads (UNM) — External + Internal Limits, 0.30 – 1.40 mm

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 B1.10M Unified Miniature Screw Threads (UNM) — External + Internal Limits, 0.30 – 1.40 mm) 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.

At UNM scale, what actually governs a successful miniature threaded assembly — and what should be specified beyond the thread limits?

Below 1.4 mm, the thread limits on this page are necessary but not sufficient — assembly success is dominated by things the chart cannot print. Handling: a 0.50 UNM screw's pitch-diameter tolerance is 0.018 mm; a fingerprint's oil film or a single handling nick approaches that scale, so parts must be cleaned, handled with tools (never fingers) and assembled in controlled torque — gram-centimetre drivers, not feel. Gaging: GO/NOGO plug-and-ring sets become impractical below roughly 1 mm, so receiving inspection typically runs optical comparators or specialty miniature gages — name the gaging expectation at RFQ so incoming stock arrives with compatible certification. Material and finish carry proportionally more weight too: at miniature scale, corrosion eats a thread's flank fraction in months where a full-size thread shrugs it off for years, so stainless or coated parts are the default rather than an upgrade, and precious-metal or conductive finishes on electronics hardware are specified for contact resistance, not appearance. The chart's pairing logic — external below basic, internal above — still holds and the two tables on this page are the mating reference. For custom micro-fasteners with drive features (Torx-style, slotted), the head geometry comes from the ASME B18.11 page and drive-feature tolerancing is a per-RFQ drawing conversation.

What is the MOQ and lead time for threaded parts on this standard?

The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common thread sizes on this standard are widely stocked; confirm the exact schedule against quantity and size mix at quotation.