What's the difference between SDS Plus and SDS Max Drill Bits?

A common question we get asked here at Millcot Tools – what’s the difference between SDS Plus and SDS Max?

Developed by Hilti and Bosch in 1975 the SDS system is a simple click and lock system for drill bits.  There is no need for tightening any chucks as the drill bits push into the chuck and simply ‘click’ into position.  To remove the drill bits the chuck has a moveable collar which is pulled back and the drill bit can be simply pulled out again.

The key difference between SDS Plus and SDS Max is size.  The shank on an SDS Plus drill bit is 10mm in diameter and 18mm in diameter on an SDS Max drill bit.  SDS Plus is the more popular option as it is used by pretty much all small hammer drills (for drilling/chiselling masonry) on the market.  SDS Max is used on bigger machines for large diameter drill bits or for large chisels for breaking up concrete and masonry etc.