What is the standard lip clearance on a drill bit?

What is the standard lip clearance on a drill bit?

• A. 8-12 Degrees
• B. 5-7 Degrees
• C. 15-20 Degrees
• D. 25 Degrees

Answer: (A)

Lip clearance angle is the relief behind the cutting edge of a drill bit that prevents the edge from rubbing on the work as it cuts. For general-purpose twist drills, the standard lip clearance is about 8 to 12 degrees. This range provides enough relief to reduce rubbing and heat buildup while keeping the cutting edge strong and effective. A clearance of 5–7 degrees would be too little, increasing rubbing and dulling risk. Too much clearance, like 15–20 degrees or 25 degrees, weakens the edge and lowers cutting efficiency, leading to poorer hole quality and wandering.

Lip clearance angle is the relief behind the cutting edge of a drill bit that prevents the edge from rubbing on the work as it cuts. For general-purpose twist drills, the standard lip clearance is about 8 to 12 degrees. This range provides enough relief to reduce rubbing and heat buildup while keeping the cutting edge strong and effective. A clearance of 5–7 degrees would be too little, increasing rubbing and dulling risk. Too much clearance, like 15–20 degrees or 25 degrees, weakens the edge and lowers cutting efficiency, leading to poorer hole quality and wandering.