Tension Control (TC) Bolts — F3125 F1852

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 (Tension Control (TC) Bolts — F3125 F1852) 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.

How does a TC bolt guarantee installed tension?

The groove between the splined tip and the threads is dimensioned so the torque needed to shear the spline corresponds to the bolt's design tension. The shear wrench turns the nut against the spline until the groove fails — at that moment the bolt has developed its tension, regardless of the torque the friction conditions consumed getting there. The crew never measures torque, and the inspector checks the joint visually: spline gone, nut not spinning free. The catch is lubrication — the shear torque depends on the as-supplied lubrication, so RCSC practice requires pre-installation verification on a tension calibrator, and lots that sat outside or rusted are re-verified or rejected.

Is a TC bolt as strong as a regular A325 bolt?

Yes at the F1852 grade: it carries the A325 strength level — 120,000 psi minimum tensile — in a twist-off assembly. The A490-strength counterpart is F2280 at 150,000 psi. Both used to be standalone ASTM specifications and are now grades under the unified F3125 structural bolt specification. What differs from a heavy hex A325 is the head geometry and the installation method, not the strength: TC assemblies are chosen for installation speed and guaranteed tension, and structural specifications accept them alongside conventional A325/A490 heavy hex bolts.

What is the MOQ and lead time for this bolt type?

The minimum order quantity is 1,000–10,000 pieces depending on size. Stock items ship in 3–7 days; high-strength and custom parts in 15–25 days. Common diameters in this bolt type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.

What should an RFQ for TC bolts state?

State the standard and grade (ASTM F3125 Grade F1852 at the A325 strength level, or F2280 at the A490 level), diameter and length, nut and washer requirements, finish (plain, mechanically galvanized, or weathering-steel type), required certificates such as a mill test report per EN 10204 3.1, and quantity per size — plus destination country.