Thread: hilti te17

I also own a Hilti, the TE22. I have one bit that won't stay in the chuck because the shank of the bit is incorrect.
Check that the bit is the right one for the chuck that is actually on the drill. I think that at some stage either the chucks changed or with the release of the competitors SDS bits that problems started. Hilti originally had their own design on the shanks.

Hi all,

Bosch SDS drill bits fit a Hilti but Hilti TE-C drills may not necessarily fit every Bosch. The TE17 was introduced in 1967 and was the first pneumatic drill that Hilti designed and made by itself. Before that the company merely serviced Torna hammer drills (license built Skil drills) and the only homemade Hilti products were gunpowder operated fastening systems. The TE 17 was spot-on and excellent from the start, though. It also introduced the TE-C drill bit bajonet system, which was Hilti's own patented development. Bosch copied this system for its own SDS-bajonet ( SDS was short for "steck, dreh, sitzt" or "insert, turn, locked") but added a lateral groove in the drill shank, meant to add just enough shape difference form the orignal Hilti shank to avoid patent infringement. The greater success and popularity of Bosch's SDS-Plus drills was merely a matter of more intensive marketing and the lower price of Bosch hammer drills.
Hilti developed the TE-C-bajonet into a larger diameter TE-Y version to be used for its TE 60 and TE 72, and Bosch resorted to the same trick for copying it into its own SDS-Max bajonet (again with additional grooves).

The failing of a Hilti bajonet can have several causes. For proper drill bit fixture it sufffices to follow three steps. First slide back the bajonet sleeve in order to insert the drill and after insertion let the sleeve spring back to the front. As second, the drill bit is to be turned inside the bajonet until the two capsule shaped locking bodies snap into the recesses that are milled in the drill shaft on opposite sides. As a third, the proper locking is to be tested by trying to pull the drill bit out of the bajonet. There should be some play forward and backward (to allow free drill bit movement during hammering), but if the drill can be pulled out of the bajonet, the locking bodies did for some reason not fit properly inside the shaft recesses. This may be caused by the bodies being stuck (debris inside the bajonet or lack of lubricant). Also, the wear may have grown to such extent that the bodies have too much play and cannot be pushed deep enough into the recesses. As a third measure, check the edges of the recesses in the drill bit shaft. Severely used bits often show shaft recesses with frayed edges, allowing the locking bodies to be forced out of the recesses when torque is exerted on the drill bit. If all of this fails, take the bajonet apart to have a look inside what's wrong with it. When clear signs of wear, damage or play are visible, replace the bajonet. Spares can be ordered through Ebay. Broken TE 17's with motor or piston damage are often offered as part sources. The bajonet of the TE 17 and TE22 are interchangeable. If used spares are unavailable, newly made Chinese counterfeit bajonets will do, since nowadays they are decent quality.

success and greetings

gerhard

Thank you for your reply gerhard.

One of my drill bits for some reason does not have two recesses (I think, will look and confirm) and there fore does not stay in the chuck.

I have found putting a little bit of grease on the shank makes it easier to insert and release the bit. What type of grease should I be using, or does it not matter?

Hi Handyjack,

yes, the recesses in the bit shaft are essential, without them the bit will only transfer the hammering action and the locking bodies will scrape around the smooth shaft without transfering rotation torque. Since we're on this topic, special hammering only bits were available for the TE17 and TE22, despite the fact that these models offered no setting switch off rotation during hammering. To achieve this, a little trick was devised. The section of the bit shank where the locking recesses would normally be, were treated on a lathe. In fact the depth of the recesses was cut away along the entire circumference of the locking section of the bit shank, leaving the locking bodies with free play without wear and scraping friction. The bit was also fitted with a holding handle to keep the cutting edge in front in one position, while the bajonet chuck rotated freely around the shaft and transfered the hammer blows only. These accessories are still available to diversify any rotating hammer drill into a hammering-only machine.

As for the grease, any light grease that does not attack the rubber o-ring dust seal is good enough. The grease is merely meant to reduce wear and friction heat and to absorb dust up front before it can enter the chuck. Many hammer drill brands offer such grease in toothpaste tube portion, but ball bearing grease and such will also do the trick.

greetings!

gerhard