drillling&mining drilling bucket kelly bar

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