Reamers: More than you ever wanted to know.

Reamer can simply be defined as: Any tool used to smooth, enlarge or accurately size an existing hole.

Reamer Design: Most reamers are made up of three parts:
1. Angle of chamfer. This is the part of the reamer that does all of the cutting. The flutes allow oil to reach the cutting area and also allow for chips to be removed.
2. The Body. The body is made up of flutes and lands. The land is the area between each flute. On top of each land is a margin which runs from the angle of the chamfer to the back end of the flute. Body clearance angle is the relief in the back of the margin.
3. The Shank. This is the driving end of the reamer and is the end that fits into the holder on your machine. Reamers are available with straight or tapered shanks.

Reamers can have straight or spiral flutes. Spiral flutes allow for chips to be pulled up and out of the hole and are therefore ideal to use in blind holes. While the majority of reamers are right hand cut, they can be right or left hand spiral. Let me explain the difference:

Right Hand Spiral / Right Hand Cut:
- chips flow up the flutes and out of the top.
- suitable for blind holes

Left Hand Spiral / Right Hand Cut:
- chips flow in the direction of the feed
- typically used for through holes
- preferred method for interrupted holes

High Spiral Flute:
- typically used for soft and gummy materials
- usually allow for faster speeds and feeds

Application and Use of Reamers:

It is always best to leave as little stock as possible for the reamer to cut. How much? Well here is a good guideline for you.

Stock Removal for Machine Reaming:
To 3/32" .003 - .006
Above 3/32" to 1/4" .008 - .010
Above 1/4" to 1/2" .012 - .015
Above 1/2" to 1" .017 - .020
Above 1" to 2" .020 - .025
Above 2" .030 - .035

Stock Removal for Hand Reaming:
All sizes .002 - .004

A reamers must be in proper alignment with the hole to be reamed. This means the spindle and hole to be reamed must be in proper centerline alignment in order to assure that the hole produced is straight and well machined. Proper alignment will also prolong tool life. A sure sign of misalignment is oversized holes, egg-shaped holes and bell-shaped holes.

How many different types of reamers are there? Many. Here they are with quick definition.

Hand Reamers:
Basically a finishing tool it should never be used under mechanical power. It is not advisable to leave more than .005" stock to be removed for hand reaming.

Taper Pin Reamers:
Used to ream holes to suit taper pins. Makes sense right? typically you will want to predrill the hole with a tapered drill.

Taper Pipe Reamers:
Ok, getting basic here but these are typically used to ream holes to suit tapered pipe taps. You should also use a tapered drill to generate this hole.

Taper Shank Jobber:
Longer flute length compared to standard reamers.

Speeds and Feeds can be found on the www.toolinghouse.com website under Technical Sheets. As always you can contact us at anytime with tooling questions or concerns.

At www.toolinghouse.com we are pleased to offer one of the largest selections of Reamers in HSS, Cobalt and Solid Carbide. US Made.