Forged Steel Fittings

Forged Steel fittings are the fittings made by forged Steel. The process of manufacturing forged Steel fittings include: cutting and heating billets, put pressure on heated billets under dies into desired shape, trimming and shot blasting. Then machine forged blank fittings for net shape and dimensions.

According to the applications of forged Steel fittings, they are available in threaded and socket weld end connections. The dimensions for socket weld forged Steel fitting conform to ASME B16.11 and threaded forged Steel fittings conform to ASME (American Society of Mechanical Engineers) B1.20.1.

 Most of the forged Steel fittings are not large, so closed die forging is normally adapted to produce forged Steel fittings. Close die Forging is a plastic deformation process where, unlike in the open die forging process, the material is forced to flow between closed dies. Compared to the open die forging, the close die forging (said also hot drop forging) can achieve more complex geometries, very much close to the dimensions of the finished component. The plastic deformation is given rapidly through some shots which force the material to fill the shape of the die. The process is performed at the plastic temperature of the material in use without intermediate re-heatings.

Close die forging can produce forged Steel forgings in all types of forged Steel fittings, no matter it is carbon Steel or stainless Steel. Closed die forged Steel fittings shows several advantages like the typical flow lines of the material along the profile of the component, beneficial particularly on mechanical components put in service under cyclic fatigue. This process allows furthermore to use reduced over-dimensions, feature which allows cost savings on input weights as well as on final machining due to less material to remove.

The two major types of threads are the BSP and NPT, which are not compatible one with the other:

BSP Fittings

BSP means “British Standard Pipe” and can be further divided into the BSPT (tapered) and BSPP (parallel) variations. The threads have a 55° angle in this case. BSP threaded fittings are less common than NPT threaded fittings in the oil and gas industry

NPT Fittings

NPT stands for “National Pipe Tapered” and is the dominant standard for threaded forged fittings in the oil and gas industry. NPT threading is covered by the ASME B1.20.1 specification and is based on 60° thread flank angles (vs. 55° of the BSP type).

FORGED FITTINGS MATERIALS

Carbon Steel fittings ASTM A105 (forged)

Low-alloy Steel fittings ASTM A182 (forged)

Stainless Steel fittings ASTM A182 (forged)