SDS vs SDS Plus vs SDS Max

[Awlknottedup]

I just bought an SDS Max hammer drill off Craigs list. I want to know the differences between the various bits. It will be used to drill several 1 1/2" and 9/16" holes through 6" concrete.

I saw some bits in a pawn shop and wanted to know the differences.

 

[DH in Carolina]

The Sds drive was brought out by Bosch as away to hold hammer drill bits. The SDS is for smaller bits and will interchange with SDS plus. The SDS plus has a stronger end than the SDS bit. The SDS Max has a larger end and will not interchange with SDS or SDS plus. You can get an adapter to make sds bits work. There is also a spline drive system which has evenly spaced splines on the drive end and it will not interchange with sds or sds max. DH

 

[awkknottedup]

I found this on an Ebay listing:

A: SDS stands for Schnell Drilling System or Slotted Drive System. All modern rotary hammers use one of three types of bit: SDS, SDS-MAX, and SPLINE SHANK.


SDS is also and confusingly called "SDS-Plus" and often written "SDS+". They are all the same SDS shanks are slotted and have curved recesses all of which lock nicely into the chucks of "SDS rotary hammers." They are the smallest of the three shank types, so the biggest diameter SDS bits you'll find are about 1-1/8 inch.

SDS-MAX is the "super colossal" version of SDS-Plus. SDS rotary hammers drill and pound bigger holes (up to 2") with longer bits (up to 28" or so). SDS-MAX hammers have lots of power, so not only is the hammer drilling faster, the chipping function is extremely useful. Most of these large rotary hammers, however, cannot be used as plain drills like their smaller (SDS+) cousins. They have just two "modes": "hammering with rotation" or "hammer only," and the same is true of almost all Spline Shank hammers.

Spline Shank is a bit more confusing because the drill bits for this system have a different-looking shank than the chisels. The drill bits have fins (or "splines") at the end of the shank while the chisels and other hammer tools have a hex shank with a deep indent on one side for the lock. But if the bit says "spline," it is, and it'll fit these tools.