I'm having a tough time finding anything on Hilti date codes, does anyone know where to point me?
Reason is it's probably older'n you are!
There was never much of a handbook on the TE17. Its original carrying case came with a 12 page brochure, containing a few pages about the workings and the maintenance, with the remaining print being dedicated to the available accessories and their application.
The machine itself is simple enough. Hilti introduced it in 1967 and so there's no electronics or left/right rotation option yet. Between the drill bayonet and the cast motor and gear housing is a rubber clad studded bajonet, surrounding the piston system. By rotating it and shoving it forward towards the drill bayonet (with a few centimeters of blank alloy cylinder becoming visible) you decouple the hammering mechanism, leaving you with a rotation-only machine. By shoving back and locking the rubber housing bajonet, you combine the rotation with the hammering function again.
The TE17 was Hilti's first hammer drill construction. The brothers Martin and Eugen Hilti started off their small scale machine parts manufacturing shed in Schaan (Liechtenstein) in 1941 and mainly catered for the Swiss textile industry. The brothers were sort of gun nuts. Upon learning about shockwave projectile propagation behavior in solid materials (e.g. artillery shells or hardened steel nails in stone walls) they invented gunpowder driven systems to shoot fastening systems directly into stone without multi-blow hammering or pre-drilling. The development started in 1948 and resulted in the piston and powder cartridge type nail shooter in 1958, for which the main Hilti factory in Schaan was built in 1954.
Contrary to popular belief, the pneumatic hammer drill was not invented by Hilti but by Skil in 1962. Skil's first large commercial hammer drill was the 726 from 1964. The Swiss firm Torna acquired production license rights from Skil USA and built the 726 as the Torna 765 for the European market, from 1965. Hilti acquired service and repair contract rights from Torna; Torna machines could be handed in at Hilti sales points for servicing. Hilti took over part of the Torna production in 1967 and a developed a smaller version for its own brand. This was to become the TE17.
The TE17 has become a bit of a legend on its own accord. The number is related to Hilti's very own advanced capacity measuring system in concrete: the amount of cubic centimeters of concrete compactness grade B30 that can be drilled out in 1 minute.
This way of measuring automatically takes the drill diameter into account: a smaller diameter penetrates quicker than a larger diameter drill, but the volume of material drilled out is roughly the same. So (e.g.) a TE22 achieves 22 cm3 per minute and a TE72 can manage 72 cm3. The TE72 has an alternative version, the TE60, with a higher rpm and a smaller compression cylinder ).
The TE17 also pioneered Hilti's new patented bayonet drill coupler. To insert the drill, the machine was to be placed on its rear grip with the coupler sticking up. In this position the bajonet's outer bush could easily be slid backward, retracting two cylindrical couplers meant to fit two recessed grooves on either side of the drill shaft. After greasing the shaft and inserting it into the bajonet, the bayonet was to let go and sprung forward automatically. The drill bit was to be turned around until the coupler bodies clicked into the recesses and as a check, the drill had to be tested for approx 1/2 a centimeter of free play forward and backward. This play is necessary to relieve the bajonet itself of the hammering impact forces. Hilti named this bajonet coupler system TE-C and developed the heavier TE-Y version for larger diameter drills. Bosch was keen to take over this brilliantly simple and reliable bayonet solution for its own drills, and averted patent infringement problems by adding an additional slot in the shaft and calling their own shape SDS-Plus ("Steck-Dreh-Sitzt" or "Insert-Turn-Secured"). The copying trick was later pulled off by Bosch for the second time with the TE-Y bayonet: SDS-Max.
The first TE17's have an all metal drill bayonet coupler, with a gnurled bush. Later version have a larger plastic clad bajonet, that was also used on the TE22. The shaft and bajonet designs of the 17 and 22 are interchangeable. In the pics you see the vintage and the later bayonet. The TE22 as a successor featured a 520 Watts motor (450 Watts for the TE17) and rpm-electronics. The first TE22's were also full metal, later version had a nylon motor housing.
Be sure to lightly grease the drill shaft before inserting it, it greatly reduces wear on the bayonet, the couplers, the drill shaft and the dust seal.
The TE17 was so successfull that its size and build were copied many times over. Examples are the Makita HR2510 and the Hitachi DH25V and their predecessors. The TE17 and its larger sister TE72 greatly contributed to Hilti's fame in this field and were obviously even able to mask the fact that they were not Hilti's own original idea (although a bit of the masking was also the result of Hilti's own clever PR).
It is not advised to take a Hilti hammer apart when you're not experienced in doing so and without having an assortment of spare parts ready for backup. Many parts are non-standard and are no longer made or sold by Hilti anyway. Many parts advertised on eBay for the TE17, TE22 and TE72 are Chicom. The TE17's bottom motor bearing is a sintered bronze sleeve and has unique sizes. Many ball and needle bearings have unique custom made sealing systems, because of the oil filling instead of grease lubrication. If your TE17 is in good shape and in any way dear to you, a servicing by a Hilti technician will pay off. He will check all seals and bearing and has the means to check on proper piston pressure, ensuring proper hammering force. A leaky Hilti is no fun at all. Is messes up its surroundings and oil dripped into the motor will definitely ruin it. If you're sure that a Hilti performs well and has a good fill of oil, the phrase "if it isn't broken, don't fix it" is very apt.
jack vines
