K800 Round Magnet
Other printer parts · 2 thicknesses · 2 hole diameters · 2 options in stock
Small printer parts that do not fit a single category — check the dimensions rather than the name. 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 2 options: Thickness 3–4mm (2 options), Hole diameter 3–4 (2 options). From ¥0.38.
The parts of this item
Figure 1 — A magnet needs four numbers: diameter × thickness × grade × plating — one grade down loses about a third of the pull
What each parameter decides
Every parameter below shows the real range available on this page, and what goes wrong if you pick it wrong. Work through them in this order and you will not go far wrong.
| Parameter | Available here | What it decides | If you get it wrong |
|---|---|---|---|
| Thickness | 3–4mm (2 options) | stiffness and the space it takes | too thin deflects, too thick will not fit |
| Hole diameter | 3–4 (2 options) | whether it fits your shaft | too big rattles, too small will not go on |
How to choose, step by step
- Choose the thickness — This page has 3–4mm (2 options). Stiffness and the space it takes.
- Choose the hole diameter — This page has 3–4 (2 options). Whether it fits your shaft.
How the options on this page are distributed
Figure 2 — how the 2 options on this page are spread across each parameter: the bars on the left show how many options sit in each band, the panel on the right shows the real range of every parameter and how many steps it has.
Variant quick reference
| Thickness | Hole diameter | Part no. |
|---|---|---|
| 3 | 3 | P3-010-HD3-K3 |
| 4 | 4 | P3-010-HD4-K4 |
Reading the part numbers
| Part no. | Configuration |
|---|---|
P3-010-HD3-K3 | Thickness 3 · Hole diameter 3 |
P3-010-HD4-K4 | Thickness 4 · Hole diameter 4 |
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.
5 common mistakes
- Measure before ordering. Parts in this group are not standardised and a model number is not enough.
- Watch the units. Mixing mm and inch is the single most common mistake on parts like these.
- Check the mating part too. The part can be right and still not fit what it bolts to.
- 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.
- 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.
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:
- Judge by the part: wear, deformation, growing play or noise all mean replace.
Fitting and use
Before you fit it
- Measure the part you are replacing, not the drawing. On a machine that has been running, the drawing and the machine are rarely the same.
- Check the mating part as well — a correct part on a worn mating face still does not fit properly.
- Lay the new part next to the old one before you take anything apart. If they do not match, you have found the problem before the machine is in pieces.
Fitting
- Clean the mounting faces. A burr or a chip under a bracket puts it out of square and no amount of tightening fixes it.
- Bring fasteners up finger tight first, then torque in a cross pattern. One screw taken to full torque first pulls the part off position.
- Check freedom of movement before final tightening. If it binds, it is misaligned, not tight.
After fitting
- Run it through the full travel by hand, slowly, before applying power.
- Check again after the first hour of use — fasteners settle and things move.
- Keep the old part. If the new one fails you want something to compare against.
Do not
- Do not force a part that does not fit. It is the wrong part or it is not square, and forcing it damages both.
- Do not reuse a fastener that has already been stretched or has damaged threads.
- Do not skip the alignment check to save time. It is the cheapest step and the one that decides how long the part lasts.
Matching parts
- Matched to the specific part
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.