STI Taps

Recoil® Taps, Helicoil Taps, STI Taps, or Screw Thread Insert Taps are used with Recoil® Inserts or Helicoil Inserts only. Recoil® STI taps are manufactured to precise standards from High-Speed Steel (HSS) with ground threads and are available in Taper, Intermediate, and Bottoming lead. They have a large diameter but the same pitch as a standard tap to accommodate the Recoil® Inserts. 

Spiral Point and Spiral Flute, machine taps are available. For all spark plug applications, pilot nose taps are available. Recoil® thread inserts, when installed into a correctly tapped hole, will provide the applicable internal thread tolerance for the installed bolt.

In the unified thread system, the minimum pitch diameter for a 2B hole (medium fit) or 3B hole (close fit) are the same, while the maximum pitch diameter is greater on the 2B hole (medium fit). Recoil® taps for unified threads are made to a 3B hole (close fit) tolerance.

In the metric thread system, the minimum pitch diameter for a 5H hole (medium fit) or 4H5H hole (close fit) are the same, while the maximum pitch diameter is greater on the 5H hole (medium fit). Recoil® taps for metric threads are made to 4H5H hole (close fit) tolerance.

Recoil® taps or Helicoil STI tap sets are manufactured for every thread form, including UNC, UNF, BSC, BSW, BSP, BSF, BA, NPT, and ISO metric thread sizes.

Recoil STI taps or Helicoil taps are available in sizes M2 to M52, UNC 2-56 to UNC 1-1/2-6, UNF 3-56 to UNC 1-1/2-12, 0BA to 6BA, BSC 5/16 to BSC ½, BSF 3/16 to BSF 1-1/4-9, BSP 1/8 to BSP 1-11, BSW 1/8 to BSW 1-1/2-6, NPT 1/8 to NPT1-11, UN 1-1/8-8 to UN 3-8 and Spark Plug Sizes M10x1, M12x1.25, M14x1.25, M18x1.5.