38
THECORRECT USEOF REAMERS
A guide to successful reaming
•
Make sure the workpiece is securely held and supported.
Should it bend or move, it could result in a poor finish or
cause the reamer to break.
•
Use a good morse taper sleeve and thoroughly clean both the
sleeve and the taper shank of the reamer.
•
As a reamer only cuts on the bevel lead and not on the
peripheral land, it is essential to keep it sharp. A blunt
reamer wears on the outer corners on the bevel lead,
resulting in a poor fininsh, undersize holes and increased
torque. (See page 39 for re-sharpening details.)
•
Direct an adequate supply of the recommended lubricant to
the cutting area. When reaming high tensile materials, an
improved surface finish can be achieved by using
chlorinated or sulphurised oils.
Stock Removal
Reamers are used to produce accurate holes with a good surface
finish. It is a common fault to leave too little stock for removal by
reaming. This results in a rubbing action and excessive wear of the
reamer. The table below shows approximate amounts of stock to be
removed by reaming.
Machine Reamers
Above
1.5
3
6
13
25
Up to
1.5
3
6
13
25
Pre-Drilled
(mm)
Pre-Core
Drilled
(mm)
Size of Reamed
Hole (mm)
0.3
0.3
0.3
0.4
0.5
0.5
0.2
0.2
0.2
0.25
0.3
0.3
Hand Reamers
The hand reaming allowance should be approximately two thirds of
the machine reaming allowance.
