What is the most common drill bit shank?

Round shank is the most common shank for standard twist drill bits and works with ordinary keyed or keyless drill chucks.

What is a hex shank drill bit used for?

Hex shank drill bits are commonly used with quick-change holders and cordless drivers. They reduce slipping compared with smooth round shanks in many light-duty jobs.

What is the difference between SDS Plus and SDS Max?

SDS Plus is smaller and common for medium-duty hammer drilling. SDS Max is larger and used with heavier rotary hammers for bigger concrete holes.

Drill Bit Shank Types: Round, Hex, SDS Plus, SDS Max and Reduced Shank Explained

The cutting part of a drill bit gets most of the attention, but the shank decides whether the bit fits the machine. A good drill bit with the wrong shank is still the wrong product.

Drill Bit Shank Types - industrial drill bit selection guide cover image — Drill Bit Shank Types – industrial drill bit selection guide cover image

This guide explains the shank types that buyers most often see in industrial, construction and hardware markets.

Quick Shank Selection Table

Shank type	Where it fits	Best use	Common caution
Round shank	Standard drill chuck	General HSS twist drilling	Can slip if the chuck is weak or oily
Hex shank	Quick-change holder, cordless driver	Fast bit changes, light metal, wood, plastic	Not always ideal for precision deep holes
SDS Plus	SDS Plus rotary hammer	Concrete and masonry holes, common sizes	Not compatible with normal drill chucks
SDS Max	SDS Max rotary hammer	Large concrete holes, heavy-duty work	Too large for SDS Plus machines
Reduced shank	Smaller chuck with larger cutting diameter	Large holes with common drill chuck sizes	Machine power and rigidity must be enough
Morse taper	Industrial drill press, lathe tailstock	Large industrial twist drills	Must match the machine taper size

Round Shank

Round shank bits are the standard choice for common twist drill bits. They are easy to produce, available in many sizes and fit most keyed or keyless chucks. For HSS drill bits sold through hardware channels, round shank is the default.

Hex Shank

Hex shank bits are useful when the user wants quick changes. The six-sided shank also reduces slipping compared with a smooth round shank. They are common in cordless driver sets, mixed drill-and-screwdriver kits and light-duty jobsite applications.

For precision drilling in metal, however, a normal drill press and round shank may still be better because runout control is easier.

SDS Plus and SDS Max

SDS shanks are for rotary hammers. The bit can move back and forth under hammer impact while still transmitting rotation. This makes concrete drilling much more efficient than a normal chuck.

SDS Plus is the most common construction size for medium-duty concrete holes. SDS Max is larger and used for heavy-duty concrete drilling and demolition accessories.

Related reading: SDS vs SDS Plus vs SDS Max.

Reduced Shank

Reduced shank bits have a cutting diameter larger than the shank diameter. For example, a large bit may have a 1/2 inch shank so it fits a common chuck. This can be useful, but buyers must confirm the machine has enough torque and rigidity.

Morse Taper

Morse taper shank bits are used in industrial machines such as drill presses and lathes. They provide strong alignment and torque transfer for larger drilling work. The buyer must confirm the taper number, not only the drill diameter.

Buyer Takeaway

When quoting drill bits, always confirm the machine chuck or holder. Diameter and material are not enough. The shank type must match the customer’s equipment.