Imperial fasteners are still widely used in the United States, Canada, and many maintenance markets supplied by U.S.-standard equipment. For importers and distributors, the main challenge is not only stocking inch sizes. It is identifying the correct diameter, thread series, length, grade, and matching parts before placing the order.

A 1/2 inch bolt and an M12 bolt may look close, but they are not interchangeable. The thread system must be confirmed first.

What Imperial Fastener Sizes Mean

Imperial fasteners are usually specified by fractional diameter, thread count, and length. A common description looks like this:

1/2“-13 UNC × 2“

Das bedeutet:

• 1/2 inch nominal diameter
• 13 Fäden pro Zoll
• UNC Grobgewinde
• 2 inch overall length

For regular stock items, buyers can review Standardbefestigungen und Bolzenprodukte bevor Sie ein RFQ vorbereiten.

Common Imperial Bolt Size Chart

This chart is useful for first checking, but final orders should follow the required ASME, ASTM, SAE, or project standard.

UNC vs UNF: Which One Should Buyers Stock?

UNC Coarse Thread

UNC is common for general industrial use. It is easier to assemble, more tolerant of dirt or minor damage, and widely stocked.

UNF Fine Thread

UNF is often used where finer adjustment, stronger thread engagement, or vibration control is needed. It is common in automotive, machinery, and equipment repair markets.

For non-standard inch threads or special lengths, use kundenspezifische, nicht standardmäßige Verbindungselemente.

RFQ Checklist for Imperial Fasteners

Bevor Sie ein Angebot anfordern, stellen Sie Folgendes bereit:

1. Durchmesser und Länge
2. UNC, UNF, or special thread
3. TPI value
4. Head style and drive type
5. Material und Qualität
6. Oberflächenveredelung oder Beschichtung
7. Passende Muttern und Unterlegscheiben
8. Anforderungen an Verpackung und Kennzeichnung

For complete sourcing, review the full Verbindungselemente range. If washers are included, check Waschmaschinenprodukte for matching sizes.

Abschließender Rat

Imperial fastener sourcing should never rely on visual comparison. Importers and distributors should confirm diameter, TPI, thread series, length, grade, finish, and matching parts before ordering. This prevents wrong-thread inventory and reduces customer complaints.