1/2 handle woodworking knife

Cutting tools · 1 option in stock

Cutting tools for CNC and hand use — taps, end mills, collets, drills. The parameters are listed in order of importance: the one at the top decides the most, and no amount of care further down makes up for getting it wrong.

This page lists 1 option, from ¥23.4.

What this part is

1/2 in shank bottom-cleaning router bit. The cutting edges are on the end, so it flattens the floor of a groove or a pocket. Used for shallow grooves, surfacing, and cleaning up the bottom of a joint.

The parts of this item

Figure 1 — The same cutter will not go in if the shank does not match the collet; get the cutting diameter 0.5 mm wrong and the slot is 0.5 mm wide.

The parameters that matter

Not every number on a part like this is worth the same. These are the ones that decide whether it fits and works, and what to look at for each.

How to choose, step by step

1. Start from the material — Aluminium, steel, stainless, acrylic and wood each want a different substrate and a different geometry. There is no one tool that cuts everything well.

Reading the part numbers

You can order by part number or by selecting the parameters. The part number is fastest, but it does not always encode every parameter — the selector on this page is the authority.

7 common mistakes

1. 3.175 mm and 4 mm are different specs. 3.175 mm is imperial 1/8", common on small desktop routers; 4 mm is metric. A collet that does not cover the size will not hold it.
2. Taps come in coarse and fine pitch. M10×1.5 is coarse, M10×1.25 is fine. The wrong one binds after two turns, and forcing it ruins the thread.
3. The ER number sets the clamping range. ER11 holds 1–7 mm, ER16 1–10 mm, ER20 1–13 mm. An ER11 will not take an 8 mm tool, at all.
4. Coating is not decoration. TiN suits steel, DLC suits aluminium and non-ferrous. Swap them and you get sticking or very short life.
5. Flute count follows the material. Aluminium wants 1–2 flutes for chip room; steel wants 4 for rigidity. A 4-flute cutter in aluminium welds up.
6. Measure before you order. Take the old part off and measure it, or send us a photo with the caliper reading — that beats guessing from a model number every time.
7. Everything here is in millimetres. Where a size is imperial, convert it: 1" = 25.4 mm, 1/4" = 6.35 mm, 3/32" = 2.38 mm.

Telling it apart from lookalikes

Against a straight grooving bit: a straight bit cuts on its side and can only cut sideways. A bottom-cleaning bit has end teeth, so it can face off a surface and true up a groove floor.

Confirming it is the right part

This page has one configuration, so there is nothing to choose — which makes confirming that it is the right part more important than studying the specification. Three steps is enough:

1. Measure the mating dimension — the one place this part touches something else: bore, shaft, thread, tube OD, or hex across flats. It is the number people get wrong, and half a millimetre out means it will not fit.
2. Measure the outline and the mounting hole spacing. Two parts that do the same job from two makers often differ by 2–3 mm between holes: it looks like it will fit, and it goes on crooked.
3. Send us two photographs: one general view showing the machine and where the part sits, and one close-up with the caliper reading in shot. If the machine has a nameplate, include it — plenty of these parts are specific to one machine, and the model number locates them faster than dimensions do.

When to replace it

You do not replace this until it fails — but "still looks usable" and "still reliable" are two different things. Any one of these and it is time:

• The edge is bright and reflective — it is dull, cutting force is up and the sound has gone sharp.
• Chipped or missing teeth, and visible marks on the finished surface.
• Coating worn through to the substrate, or aluminium starts welding to the edge and building a built-up edge.

Fitting and use

Clamping

• Wipe the shank and the collet clean. A single chip is enough to give you runout and an early chipped edge.
• Follow the tool maker's clamping length: too little and it pulls out, too much and the overhang is soft and the tool deflects.
• Indicate the tool after clamping. Over 0.02 mm of runout and you should reseat it.

Cutting data

• Start slow with a light feed, listen to the cut and look at the chip colour, then work up.
• Aluminium takes high rpm and fast feed; steel needs lower rpm and coolant, always.
• Keep the entry steady. Sudden increases in depth of cut are what break edges.

Maintenance

• Clean the chips off and oil it after use. Do not clean coated tools with a wire brush.
• Replace or regrind as soon as it dulls. Forcing a dull tool raises cutting force, loses the size and eventually snaps it.
• When tapping, go in one turn and back half a turn to break the chip. In a blind hole this is not optional — pack the chip in and the tap breaks off inside the part.

Three things not to do

• Do not use the wrong shank diameter. It will not clamp, or it will not clamp tightly, and it comes out at speed.
• Do not cut steel at high speed without coolant. The tool is gone in minutes.
• Do not use a tap as a reamer. The load path is different and it will break.

Matching parts

• ER collets and nuts — matched to the shank
• Cutting fluid — essential in steel
• Tool setter and dial indicator — for setting up

Lead time, custom work and shipping

• Stock sizes: dispatched in 1–2 working days, subject to stock
• Custom: non-standard sizes, materials and treatments are possible — send quantity and drawing
• Shipping: from Shenzhen; domestic courier by default, DHL or dedicated line for export
• Volume: quantity pricing available, contact us for a quote

If you cannot find the size you need, or you are not sure which one fits, send us the problem you are solving — what machine it goes on, the dimensions of the part you have, what it has to achieve — and we will match it.