1. High quality and reasonable price. 2. Taper drill pipe and integral drill pipe. 3. Durable steel material for longtime use.

Taper drill pipe

1) Taper angle (degree): 4.46, 6, 7, 11, 12

2) Shank size: hex 22mm*108mm/25mm*159mm

3) Length: 0.4m-10m 

Different rock formations and rock drills require different taper angles. When drilling with high impact hydraulic rock drills in medium-hard to hard and abrasive rock formations, a wide taper angle is normally used. Taper angles of 11 and 12-degrees are normally used on modern drill rigs. For low impact rock drills and softer rock formations, a narrow taper angle of seven degrees is used. A 7-degree angle can also be used if bit spinning is a problem when using 11 and 12-degree equipment. In addition, a 4,46 degree angle is ideal for soft rock when you're using pneumatic or hydraulic drill rigs - to prevent bits from spinning or becoming detached.

drillling&mining drilling bucket kelly bar