1. Reamer by hand

Rose or fluted reamers, which feature a little taper on the cutting edge to facilitate reamer entrance, are types of hand reamers. These reamers may be extendable or solid. Its expansion is limited to a certain extent, though. Furthermore, the hand reamer’s blades are arranged erratically throughout its body to reduce chattering.

2. Reamers that float

Erroneous alignment between the reaming process tool’s axis and the previously drilled hole can be fixed using these reamers. With two interchangeable and adjustable cutting blades, floating reamers are allowed to float radially while being kept together in a single slot. Turret lathes with rotating workpieces are the ideal application for these reamers.

3. Reamers made of shell

When shell reamers are used with shell reamer arbors, the reamer hole fits the best. In order to achieve the desired size of well-finished reamed holes and free-cut material, these reamers are specifically developed.

Lathes, drill presses, automated screw machines, screw machines, and more all utilize them. For your large-hole reaming activities, shell reamers are an affordable choice.

4. Reamers made of carbide

High abrasion resistant areas are best suited for carbide reamers, which provide a longer tool life and a superior finish for the hole. Instead of wasting time on the previously drilled hole, solid carbide reamers create a perfect hole around their axis.

Typical Issues that Arise During Reaming

When attempting to ream a hole in a workpiece, a number of issues arise. These include:

1. Due to misalignment and improper feed and speed, the reamer creates large holes or undersized Bell-mouths.

2. High surface roughness, improper tool material, or insufficient cutting fluid flow to the cutting region might cause the reamer to seize and break.

3. Uneven chamfers, noise, excessive spindle run-out, or inadequate cutting action can all cause the reamer to degrade the hole’s surface quality.

4. Because of misalignment or excessive reaming pressure, there is excessive tool wear or breakage.

Advice and Safety Measures for Reaming Operations

To ensure a successful operation, there are a few useful pointers and safety measures to take into account during reaming. Here are a few of them:

1. Speeds and Feeds for Reamers

The material that requires CNC reaming, the type of machine, and the necessary polish and precision may all have a considerable impact on the feeds and speeds for reamer machining. About two-thirds of the feeds and speeds used for drilling holes in the same material are typically employed for machine reaming.

Reaming metal usually uses feeds that are 200% to 300% of drill feeds, which is greater than those used for drilling. Too little feed might lead to excessive reamer wear. Because of this, the feeds need to be high enough so that the reaming tool may always cut rather than rub or burnish.

2. Proper alignment

The reaming procedure depends on the spindle, bushing, reamer, and hole to be reamed all being perfectly aligned. Additionally, the helix angle needs to be appropriately aligned with the other parameters. Any change has a strong chance of increasing reamer wear and hole accuracy deviation.

In the meanwhile, you must verify that these criteria line up with holes that are bell-mouthed, tapered, or large. Adjustable holders can occasionally reduce mistakes caused by misalignment.

3. Regrinding Reamers

Making ensuring a tool doesn’t become very dull before it is changed or sharpened is one of the cutting tool tenets. A reamer’s chamfer should be regrinded before it wears out or stops cutting.

However, only the chamfer or entering taper can be sharpened. The tool is prone to cutting oversize, so you have to be quite cautious to sharpen each flute uniformly. Because it is difficult to maintain consistent cutting edges, it is not recommended to sharpen the chamfer by hand.

4. Pay Attention to Stock Allowance

For reamer machining, the stock allowance is.010 on a ¼” hole,.015 on a ½” hole, and up to.025 on a 1½” hole. However, because it is more difficult to force the reamer through large stock, hand-reaming has a significantly lesser stock allowance. Therefore,.001 to.003 is a typical allowance for a hand reamer.

5. Steer clear of chatter

The reamer and the hole’s finish are harmed by chatter during reaming operations. The machine’s lack of stiffness, too much clearance on the reamer, too much reamer overhang, and an excessively light feed can all cause chatter. Reduce the cutting speed and raise the feed rate during a reaming operation to reduce or eliminate chattering.

How Can I Calculate a Ream Hole’s Size?

When opposed to boring, reaming is a more effective and quick method of completing a hole. However, the size of the hole is a crucial factor to take into account while reaming it. The reamer would have trouble doing its function if the hole was too big. Similarly, it is ineffective to make the hole too tiny. To achieve the greatest results, you must drill the hole you wish to ream to the proper size.

The general rule of thumb is to leave between 0.010 and 0.015 inches of material behind after drilling so that the reamer may scrape it. There should be 0.003 to 0.006 of material to be extracted using CNC reaming for small diameters, such as 1/32 or smaller.

It would be preferable, though, to use a percentage rather than a set range. Making the hole’s diameter 2% to 3% less than the reamer’s would be beneficial. If the circumstances allow, you can adjust the hole’s diameter such that it is 5% less than the reamer’s diameter.