BS 328-5:1983

What is BS 328-5 - Countersinks and counterbores about?  

BS 328-5 is the fifth part of the BS 328 multi-series on drills and reamers. 

BS 328-5 specifies the dimensions of the following: 

• Counterbores with morse taper shanks and detachable pilots 
• Countersinks with parallel shanks 
• Countersinks with morse taper shanks 

Who is BS 328-5 - Countersinks and counterbores for? 

BS 328-5 on specifications for the dimensions of countersinks and counterbores is useful for: 

• Designers of drill bits 
• Drill bit manufacturers 
• Quality control personnel 

Why should you use BS 328-5 - Countersinks and counterbores?  

When screws are screwed into holes drilled by normal drills their head tends to stick out on the surface of the material. To resolve this issue countersinks and counterbore drills are used, as the holes drilled by them allow the screw head to stick inside the material and prevent the slight protrusion of the screw head. 

BS 328-5 provides dimensions and tolerances for the afore-mentioned countersinks. These dimensions enable you to produce countersinks and counterbores that drill holes specific to the commonly used screws in the industry.  

Overall, these dimensions of BS 328-5 help you in the production and quality control phases of these drill bits and thereby enhance their build quality.