K. O. LEE B360 Instruction Manual Download

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Instruction Manual

Section Five

HAND REAMER

STRAIGHT SHANK CHUCKING REAMER

INSERTED-TOOTH REAMER

ADJUSTABLE REAMER

CHAPTER 11

Reamers

A reamer is a cutting tool combining economy and accuracy for enlarging holes to

a required diameter. Reamers cut their way into holes with their leading edges

and produce a smooth finish while cutting to size.

REAMER TYPES

Most reamers fall into the following general

categories: hand reamers, straight shanked
and taper shanked machine or chucking

reamers, adjustable or expansion reamers, in
serted tooth reamers, and shell reamers. Fig

ure 49A shows the general types of reamers.

Reamers may have tapered flutes for tapered
holes and may also have spiral flutes, straight

or tapered in size.

With the exception of grinding the chamfer

or leading taper, all solid reamers are reduced

in size when their blades are ground on the

periphery. With these reamers, when the
peripheral cutting land has become dull at the
cutting edge or where other reasons dictate,
a cup wheel is used and the reamer is reduced

to the next smaller usable size Since most

dullness occurs at the lead cutting edges,

most sharpening consists of grinding only the

chamfer or lead taper.

Figure 49A

In many instances, especially with expansion

or inserted tooth reamers, it is desirable to

cylindrically grind the periphery and then "back-off a secondary cutting clearance

or relief land behind the circular land, leaving a narrow non-relieved convex land or

"margin" just in front of this relief. Refer to Chapter 2 in this section for the

general construction of reamers and their nomenclature.

Most clearance angles are critical on reamers, and it is therefore advisable to con
sult the reamer clearance charts (see tables III and IV, pages 106, 107) for the

correct amount to raise or lower the Wheelhead or micrometer toothrest. For this

reason, the tilting Wheelhead should not be used for grinding the lead taper or
the periphery of these tools as the tilting degree scale cannot be read with suffi

cient accuracy. The table is a standard one used in many handbooks, but it should
be understood that it is an approximation, as desirable margin widths and clear
ance may vary from the table with different materials to be reamed, the amount
of material to be reamed, the size of the hole, and the manner in which the

reamer is to be used.

NOTE:

Most manufacturers would probably agree with the

.006 inch recommended as a margin for hand reamers for steel. It is possible,

however, that the margin could go up to about .015 inch for some larger reamers

of this class. If cylindrically ground, the margin width left after the cutting or

secondary clearance is equivalent to the "Primary Clearance Angle" shown. The

"Secondary Clearance Angle" is the only one applied in this case. When consider
ing the margin widths recommended for other metals, some manufacturers claim
the margin can go up to 50 percent over the table recommendations for cast iron

SHELL REAMER

TAPER SHANK CHUCKING REAMER

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