Insert Types
Powercoil Free Running Inserts
Powercoil Free Running Inserts provide strong permanent internal threads
that resist heat and corrosion. Once fitted, their position is maintained by the
action of radial pressure between their coils and the flanks of the tapped
hole. This pressure exists because the free diameter of Powercoil Free
Running Inserts is larger by a calculated amount than their installed diameter.
Powercoil Screw Locking Inserts
Powercoil Screw Locking (or prevailing torque) Inserts are of particular value
in applications subject to the effects of cyclic vibration or impact. In addition
to the benefits afforded by free running inserts, Powercoil Screw Locking
Inserts offer the additional security of prevailing locking torque.
This is achieved by the action of one or more polygonal grip coils positioned
within the insert's length, which exerts radial pressure on the male thread.
Each grip coil on Powercoil Screw Locking Inserts consists of a number of
tangential locking chords which protrude inside the minor diameter of the
normal free running coils. As the male thread passes through these grip coils,
the locking flats are displaced, exerting radial pressure or prevailing torque
on the male thread.
On removal of the male thread, the locking coils in Powercoil Screw Locking
Inserts relax to their original form, permitting repeated assembly whilst
retaining a measurable level of prevailing torque.
Thread Types
Powercoil Screw Thread Inserts are available in all popular thread types:
Metric Coarse & Fine
Spark Plug
Unified National Coarse (UNC) & Unified National Fine (UNF)
British Standards (BSW, BSF, BSP, BA, BSC)
National Pipe Taper (NPT)
8-UN Constant Pitch
Insert Length
Powercoil Screw Thread Insert lengths are calculated in multiples of the nominal thread size, or diameter, of
the insert. Five insert lengths (1D, 1.5D, 2D, 2.5D and 3D) are available for each thread size.
