The primary difference is the thread diameter and load capacity. A 1/2 socket head bolt (1/2-13 UNC) is typically used for medium-duty structural connections, while a 3/4 allen head bolt (3/4-10 UNC) is designed for heavy-duty applications requiring higher clamp loads and shear strength. Both use a hex socket drive, but the 3/4 bolt requires a larger drive size.

Yes, absolutely. Our factory specializes in custom fasteners. We can produce 1/2 socket head bolts and 3/4 allen head bolts in custom lengths, with special thread pitches (e.g., 12-24, 18-UNF), and unique head markings. Simply provide a drawing or sample, and we can create a prototype within 10-15 days.

We follow a strict 3-step QC process: 1) Incoming raw material inspection (chemical composition & hardness). 2) In-process monitoring of heading, threading, and heat treatment. 3) Final inspection includes dimensional checks (using optical comparators), tensile testing, and surface coating verification. We also provide Mill Test Reports (MTRs) with every shipment.

Our standard MOQ for stocked sizes is 500 pieces per size. For custom OEM orders, the MOQ is typically 2,000 pieces. However, we offer a "Sample Pack" option for clients who want to test the quality before committing to a bulk order.

We accept T/T (Wire Transfer) with 30% deposit and 70% against copy of B/L, and L/C (Letter of Credit) for orders over $10,000 USD. For long-term contracts, we can negotiate flexible payment terms.

For sea freight, shipping to the USA West Coast takes approximately 25-30 days, and to Europe (Hamburg/Rotterdam) takes 30-35 days. We also offer air freight (5-7 days) for urgent orders. We handle all customs documentation to ensure smooth clearance under DDP terms.

Yes, we offer free samples for standard sizes. You just need to pay the shipping cost (e.g., via FedEx or DHL). This allows you to evaluate the thread accuracy, surface finish, and mechanical properties firsthand.