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Power Tool Accessories.

Drill Terminology

Drill shanks


What is the drill shank?

The drill shank is the portion of the drill shown in the pictures below.

Effectively it is the non working part of the drill that is held in the drill chuck. There are three different types of drill shank used in the C.K range.

Straight shank

The straight shank is the most usual style used on modern drill bits. It is most often made the same diameter as the drill bit, although on Masonry drills the tip can be slightly larger than the drill shank.

Reduced shank

Where the diameter of the drill bit is bigger than can be held in a standard 13mm 3 jaw chuck, the shank is turned down.

SDS Plus (SDS+) Shank

The SDS shank has the advantage of being designed to be held in a simple spring-loaded chuck.


The bits can be loaded into the chuck by simply pulling back the collar on the chuck and inserting the drill bit.

This 'docking system' is designed to suit hammer drilling in stone and concrete.

The drill bit is not held solidly in the chuck, but can slide back and forth like a piston.


The drill bit is not held solidly in the chuck, but can slide back and forth like a piston.


The hammer of the drill acts to accelerate only the drill bit itself, and not the large mass of the chuck, which makes hammer drilling with an SDS shank drill a bit much more productive than with other types of shank. So, SDS shanks are most often seen on masonry drills, for which hammer drilling action is most helpful.


The rotational drive uses the sliding keyways that open to the end of the shank, which mate with keys in the chuck. The smaller indentations that do not open to the end are grasped by the chuck to prevent the drill bit falling out. The hammer of the drill hits the flat end of the shank. To allow the bit shank to slide in the chuck, the shank must be lubricated with grease.


SDS is short for the German "Steck – Dreh – Sitz" (Insert – Twist – Stay). German-speaking countries may use "Spannen durch System" (Clamping System), though Bosch uses "Special Direct System" for international purposes.

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