ASME B1.1 Thread Pitch Chart — UNC / UNF / UNEF / Constant-Pitch UN (0 – 2 in)

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 B1.1 Thread Pitch Chart — UNC / UNF / UNEF / Constant-Pitch UN (0 – 2 in)) 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.

UNC, UNF or UNEF — how do I choose the thread series, and when do the constant-pitch UN series matter?

The chart shows what is available per size; the joint decides which to order. UNC (coarse) is the default for general machinery and MRO: it assembles faster, strips less easily in soft materials and forgives handling damage — most stocked inch fasteners are UNC. UNF (fine) buys more: at the same nominal size it has a larger tensile stress area, finer clamp adjustment, and better vibration resistance, which is why automotive and aerospace hardware leans fine — the trade is more fragile threads and more sensitive assembly. UNEF (extra fine) exists for thin-walled parts and instrumentation, where a full thread form must fit into minimal engagement length without weakening the wall — a short-engagement thread in sheet-metal housings or tubing ends. The constant-pitch series answer a different problem: above roughly 1 in, a "coarse" or "fine" designation stops being meaningful, so the UN series fix one TPI across a diameter range — 8-UN from 1 in up, 6-UN from 1 1/8, 4-UN on the largest — keeping tooling, gages and rod stock consistent across sizes. Practical ordering: stay UNC unless the drawing or the joint demands otherwise; where it does, read the exact TPI off the chart row for the size, since misreading 28 UNF as 32 UNEF on a 1/4 in part is a real and common error.

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.