H thread steel is the most common steel and bits for contractors using hand held percussive rock drills in the US. The bit threads up to the shoulder of the steel and the percussive shock wave is transferred through the shoulder to the face of the bit. It is available in all 3 standard rock drill shank sizes - ⁷⁄₈ x 4 ¹⁄₄, ⁷⁄₈ x 3 ¼ and 1 x 4 ¼" and is intended for general duty use. Bits are available from 1-³⁄₈" to 3" diameter and come in the following configurations:

• Full carbide cross bits – Most common H thread bit as it has a deep carbide insert which will last longer and holds the gauge of the hole better.
• Shallow carbide cross bits – Good for hard rock and the short tungsten carbide inserts will deliver a moderate service life.
• Carbide button bits – Available in 1 ³⁄₈" to 2.25" diameter and prove to be more effective in very hard rock, especially when using the heavier classes of rock drills.
• All steel – Good for concrete and very soft rock applications or occasional to rare usage. You can expect a much shorter service life than a carbide bit, but there are instances when they may prove to be more econimical.

*For challenging drilling conditions, production drilling and/or when larger holes are necessary we recommend a stronger steel with a more durable thread profile, see:
1" Rope - R25 - 100 Rope or 1-¹⁄₄" Rope - R32 - 125 Rope

*For drilling small holes see: Whirly Bits