Record Power BM16, Instruction Manual, Page: 12 / 18

9b. Maintenance - Chisel and Bit
Chisel Abrasion
Look downward into the hollow of the chisel, check to see whether any of
the bevelled areas inside the chisel (where hollow becomes circular) have
dulled or any of the square corners have become round (Pic 10). The angles
of the corners should be filed to regain the original shape.
When abrasion occurs to the extent of making the thickness of the entire
chisel bit tip noticeably thin, the chisel bit will be liable to break in opera-
tion. When you see excessive abrasion, it is advisable to replace the chisel
with a new one.
To sharpen the chisel, a special chisel sharpening tool is required (Pic 11).
Part numbers for ordering these tools
R539 Set 1 (suitable for 1/4" - 9/16")
R539 Set 2 (suitable for 5/8" - 1")
There are two types of chisel sharpening tool available. One has a fixed pilot
which fits exactly into the chisel bore (each separate chisel must have a coun-
tersink with a pilot to suit each size). The other has interchangeable pilots
which are held in place by a socket screw and locked with an Allen key.
The use of this tool ensures that all four cutting edges will be evenly sharp-
ened and maintained in the correct shape and bevel.
1. Place the chisel carefully in a vice.
2. Fit the tool into a brace. Several turns of the tool will produce a fine cut-
ting edge. The inside corners of the chisel must be finished with a fine file.
Never grind a chisel. Never sharpen it on the outside. Always protect it from
possible damage.
Sharpening The Chisel And Bit
A well sharpened bit will cut fine broken chips which pass easily and quickly
through the twist and are ejected through the slot in the chisel side.
1. To sharpen the spur (Pic 12) use a small square or flat smooth file and
sharpen the inside only (Pic 13).
Never sharpen or stone the bit on the outside or attempt to grind it. If any
doubts exist at to the suitability of the bit after prolonged use and repeated
sharpening. Discard it and purchase a new one. The chisel is the more expen-
sive component and a bad bit will impose great strain on the chisel.
Pic 11
Pic 12
Pic 10
Square Corners
Bevelled Areas
Interchangeable Pilots
Pic 13
Spur
File