Portland Bolt uses National Upsetters to hot forge heads onto bolts. During the forging process, the end of the round bar is heated via an induction process and placed into the upsetter where a plunger compresses the heated steel to form the head of the bolt. Calculations are made to determine the amount of round bar which will be reshaped to create a given head style in a particular diameter, and this amount of material is added to the cut-length at the beginning of the manufacturing process. Heads can be forged onto fasteners before or after the threading process. Upsetters have an advantage over presses in that there is no length limitation with regard to bolts produced on an upsetter.
This equipment is capable of forging heads onto bolts from 1/2″ – 2-1/2″ diameter. Common head styles include hex, heavy hex, square, carriage, guardrail, timber/dome head, and countersunk. Many other head styles are currently available and we are more than willing to create new tooling for your custom requirements. We also offer the option of producing custom product with your company name and/or logo forged into the head. We forge a variety of steels including low carbon, medium carbon, alloy, stainless, and brass.