H-HSS Tapered Tap

The H-HSS Taper Tap is a High-Speed Steel (HSS) Taper Tap designed for installing Irontite “H” type Ductile Iron Plugs, including H-2 and H-4 Drilled Ductile Iron Plugs, in various casting repair applications.

The H-HSS Taper Tap is a High-Speed Steel (HSS) Taper Tap specifically designed for installing Irontite “H” series Ductile Iron Plugs. This includes the standard H plug as well as the H-2 and H-4 Drilled Ductile Iron Plugs. These “H” series plugs are part of Irontite’s range of “Diesel” plugs.

According to the specifications for the “H” plug, which utilizes this taper tap, the plug has a thread length of 1 inch and a small end diameter of 1.084 inches. The recommended drill size for preparing the hole to receive this plug is 1 1/32 inches. The corresponding HSS Taper Reamer (407-5210-80) for use with the H and H-2/H-4 plugs prior to tapping.

Irontite taper taps, including this H-HSS Taper Tap, are engineered to cut threads along their entire length. To ensure a reasonable lifespan for the tap, especially when working with thicker metal castings, it is crucial to first ream the hole using the appropriate tapered reamer (407-5210-80).

The design of Irontite taper taps and their corresponding plugs is intended to create a tight, thread-to-thread fit when the plugs are properly torqued into the tapped holes, resulting in a secure and reliable seal.

It is essential to always use a good quality tapping fluid with this taper tap. Irontite recommends their TAP-O tapping compound (468-9920-08), available in 8 oz, ½ gallon (468-9920-64), and 5 gallon (468-9926-40) sizes. TAP-O is formulated without oil or carbon tetrachloride.

The use of this H-HSS Taper Tap is integral to Irontite’s crack repair Technique, which is particularly effective for repairing areas subject to high pressure and temperature, such as valve seat areas. This technique involves a sequence of steps: drilling, reaming with the tapered reamer, tapping with the taper tap, installing and torqueing the plug, cutting off any excess plug material, and finally, peening the plug. The peening process, working outwards from the center of the plug, is vital for effectively closing the threads at the surface of the repair.