Manufacturer · Fashion & Home Accessories
The replacement slider for a YKK nylon coil zip must match three key parameters: the coil size (No. 3, No. 5, No. 8, etc.), the zip type (standard or reverse coil), and the locking mechanism. The size number is usually embossed on the back of the original slider near the YKK logo. If these three match, the new slider will function like the original.
When to look for a replacement slider for a YKK zip
For nylon coil zips, the slider is the part that wears out first. The coil itself is flexible and often lasts much longer, but the inner walls of the slider wear down with use, causing the zip to separate behind the slider. In such cases, replacing the slider restores the zip’s function without unpicking the entire garment. In mass production, replacement sliders are also needed for warranty repairs, servicing jackets, backpacks, tents, and assembling zips by the metre.
How to determine the size
1. Slider number
Check the back of the slider. YKK sliders usually have a logo and a number – for example, 3, 5, or 8. This number corresponds to the coil size. Sometimes letters follow the number indicating the slider type; these are helpful but the number is the main compatibility factor.
2. Width of the closed coil
If the slider is missing or the marking is worn off, measure the width of the closed coil with calipers. The number roughly corresponds to this width in millimetres.
| Width of Closed Coil | Approximate Number |
|---|---|
| about 4 mm | No. 3 |
| about 5–6 mm | No. 5 |
| about 7–8 mm | No. 8 |
| about 9–10 mm | No. 10 |
This table is a guideline; if your measurement is borderline, compare with a sample of a known size.
Standard or reverse coil zip
This is the most common mistake. A standard nylon coil zip shows the coil on the front side. A reverse coil zip has the coil hidden inside, with a smooth tape visible on the outside – typical for water-repellent zips and sportswear. The slider for a reverse coil zip has a different internal shape and won’t work on a standard coil zip, and vice versa. If unsure, look at the zip from the front: do you see the coil or only the tape?
Types of sliders
- Auto-lock slider – locks when the puller is released. Used for trousers, skirts, jackets.
- Non-lock slider – moves freely. Used for pockets, cases, bags.
- Pin-lock slider – locks when the puller is pressed towards the zip; convenient for jackets.
- Two-way slider – with pullers on both sides, for reversible garments and sleeping bags.
- Padlock slider – with holes in the pullers to lock together; used for luggage.
If replacing a slider in a shop, choose auto-lock again; for bag repairs, a non-lock slider is usually sufficient.
How to install a replacement slider
- Remove the top stops on one or both sides carefully with small pliers, avoiding damage to the tape.
- Pull off the old slider by sliding it upwards.
- Insert both coils into the new slider from its wide side; the puller should face the front of the item.
- Slide the slider down and check that the zip closes evenly.
- Attach new top stops or sew a strong bar tack above the coil end.
For separating zips, the slider is inserted from the top end, while the pin and box remain unchanged.
When replacing the slider does not help
Replacing the slider fixes the problem when the zip separates behind the slider and the coil is intact. It does not help if:
- the coil is broken, melted, or missing teeth;
- the tape is torn at the pin of a separating zip;
- the box of a separating zip is broken;
- the zip is too fine for the load and the problem will recur.
In these cases, the entire zip must be replaced – and it’s worth choosing a more suitable size.
Slider finish and colour
Besides technical compatibility, appearance matters for visible zips. Original YKK sliders come in various finishes – nickel colour (nickel free), bronze, black, matte silver, and also dyed to match the tape colour. If you replace only one slider on an item with two sliders, choose the same finish to avoid visible differences. The same applies to the puller shape: narrow, wide, with cord hole, with logo. For repair service, a standard puller is often acceptable, but for serial brand production it must match the approved model.
If unsure which is the original, send a photo of the slider front and back and the zip from the front – usually the number, type, and finish can be identified from these.
Sliders for serial production
For brands and workshops assembling zips by the metre, sliders are ordered separately from the coil. It is important to match size, type, and finish colour. If you work with standard nylon coil zips by the metre, Polkom offers suitable sliders in various options. For original YKK sliders, availability and compatibility are confirmed on inquiry, preferably specifying the exact YKK zip line they will be used with.
Ordering via Polkom
Polkom is a Bulgarian manufacturer of accessories for fashion, furniture, footwear, and bags, and a supplier of original YKK zips. See YKK nylon coil zips and send an inquiry with the zip number, slider type, and a photo or sample. We will confirm compatibility and offer options; minimum order quantities depend on the item.
