Spiral vs flat fretsaw blade: wander or stay on line
Updated: 22 October 2026
You are cutting a window in the middle of a panel, and turning the whole board at every corner is awkward. A spiral looks like the finer upgrade. It is not. A spiral vs flat fretsaw blade choice is about direction. The spiral cuts all round, so you can leave the work still. It also wanders, and the slot is rougher. The flat blade cuts one way, and you can steer it back to a line. Pins, tooth counts, and the clamp sequence stay on the other pages. The packs are listed on the [fret saw blades comparison](/hub/saw-accessories/fret-saw-blades).
You are cutting a window in the middle of a panel, and turning the whole board at every corner is awkward. A spiral looks like the finer upgrade. It is not. A spiral vs flat fretsaw blade choice is about direction.
You are cutting a window in the middle of a panel, and turning the whole board at every corner is awkward. A spiral looks like the finer upgrade. It is not. A spiral vs flat fretsaw blade choice is about direction. The spiral cuts all round, so you can leave the work still. It also wanders, and the slot is rougher. The flat blade cuts one way, and you can steer it back to a line. Pins, tooth counts, and the clamp sequence stay on the other pages. The packs are listed on the fret saw blades comparison.
Our top picks
| Badge | Product | Tooth path | Length | Ends | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Eclipse Eclipse 71-FS5R 18 TPI pack of 10 | Rectangular, precision milled | 125 mm | Not stated. Reviews report no pegs | 8.4 | about £5.48 | View offer |
| Best value |  Draper Draper 25510 25 TPI pin-end pack of 12 | Hardened teeth, spiral not stated | 127 mm | Pins at both ends | 7.9 | about £6.63 | View offer |
| Alternative |  Bahco Bahco 302-83S medium spiral pack of 12 | Medium spiral | 130 mm, or 177 mm on another line | Not stated | 7.0 | about £7.84 | View offer |
On this page
A cut that does not need the work turned
A spiral is round in section, so it cuts forward, sideways, or back. Bahco reviews describe internal shapes, laminate sockets, and dovetails, and also wandering, heat, snaps, and a slot too wide for a delicate pattern. You cannot nibble it back onto a pencil line. Dictum’s 0.3 mm and 0.9 mm example is not a Bahco measurement. Proxxon’s plain-spiral hole is about 1.5 mm, not a pin size. If the drawn line has to survive as a finished edge, the spiral is the wrong tool.
A line you can correct
A flat blade has teeth along one edge. If you drift off the line, you can favour one side and come back. The slot is narrower than a spiral of a similar nominal size.
Eclipse 71-FS5R describes rectangular, precision-milled teeth at 18 TPI and 125 mm. Draper 25510 states hardened steel teeth, not a spiral, at 25 TPI and 127 mm with pins. Xcalibur states a regular pitch, 24 TPI, pinned, 130 mm. None of those three is a spiral upgrade. A flat 18 TPI blade and a medium spiral are not two grades of the same thing. One steers. The other does not. Fitting either, including the ping test, is on the how to fit a fretsaw blade page.
Bahco 302-83S against the other names
Bahco 302-83S states a medium spiral, 12 blades, £7.84, 4.4 from 166 reviews, for wood and plastic. The included line says 130 mm. Trading Depot lists the same grade for Bahco 302 and 502 fret saws and gives no tooth count. The amazon dimension says 2 mm by 177 mm, so measure against 130 mm. The listing does not say pin or plain. Who should buy it is on the best fret saw blades page: internal work you will not rotate.
Titles that say spiral and are not
ZenithQuest, B0FYPN4F5G, is £6.39 for 12 blades at 12 cm, 4.0 from six reviews. The style name says spiral. The bullet says a flat serrated edge. The captured review found no spiral, and the blades snapped. That is not the spiral.
YUYTE colour 01 at £8.02 and colour 05 at £8.11 share 4.5 from 412 and the same image. Treat the texts as one pool. One review says ordinary blades arrived. Colour 05’s bullet mentions pins, and a review describes a grade without a pin. You cannot file either colour as the spiral answer. Read the bullet before the style name. A flat Eclipse or Draper pack is the safer line blade. The 16, 18, and 25 TPI chart is the buying guide.
Common questions
When is a spiral the right blade?
When the cut is internal, or awkward to rotate, and a rougher slot is acceptable. Bahco 302-83S is the medium spiral here for wood and plastic, £7.84 for 12. It is the wrong blade when the pencil line has to stay put.
Why does a spiral leave a rough slot?
The teeth run around the wire, so the kerf is wider than a flat blade of a similar nominal size. Reviews of the Bahco pack call the slot too wide for a delicate pattern. Dictum’s 0.3 mm and 0.9 mm example is not a Bahco measurement.
Can you steer a spiral back onto a line the way you steer a flat blade?
No. A flat blade has one toothed edge, so you can favour a side and return to the line. A spiral cuts in every direction, including the drift. Reviewers say it is harder to keep on a line. If the shape is a clean outline, use the flat blade and turn the work.
Which pack in this set is actually a spiral?
Bahco 302-83S, medium, wood and plastic, pack of 12 at £7.84, 4.4 from 166 reviews. The length lines disagree, 130 mm against a 177 mm dimension, and the ends are not stated. Eclipse, Draper, and Xcalibur are the flat or regular-pitch rows. Do not add ZenithQuest to the spiral list.
What if the title says spiral and the bullet says flat?
Believe the disagreement, not the title. ZenithQuest’s style name says spiral and the bullet says a flat serrated edge. The captured review found no spiral. YUYTE’s titles say spiral, and a shared review says ordinary blades arrived. Open the pack or leave it. Do not pay for a word the bullet withdraws.
Do spirals cut steel?
Not on the Bahco listing. That page names wood and plastic and does not claim metal. A spiral tooth path is about direction, not about hardness. Draper’s non-ferrous line belongs to a pin-end flat pack, not to this spiral. Do not move a metal word across from another ASIN.
How big a hole do you need before an internal spiral cut?
Proxxon’s plain-spiral note says about 1.5 mm. That is for a plain spiral, not for a pin and not for the YUYTE packs. Drill the waste, thread the free end, then tension. A pin needs a larger hole, and that size is settled with the end type, not with the spiral.
Related pages
Sources
Public UK sources from the research digest, plus the stored amazon.co.uk listings. Updated 22.10.2026.
- Spear & Jackson, Eclipse fret saw blades (retrieved 22.10.2026)
- Eclipse data sheet, fret 71-FS5R and coping 71-CP7R (retrieved 22.10.2026)
- Faithfull Tools, 130 mm fretsaw blades (retrieved 22.10.2026)
- Hobbies Yellow Label fretsaw blades (retrieved 22.10.2026)
- Proxxon DSH leaflet (retrieved 22.10.2026)
- Draper 25510 pin-end fretsaw blades (retrieved 22.10.2026)
- Trading Depot, Bahco 302-83S-12P (retrieved 22.10.2026)
- HSE: wood dust (retrieved 22.10.2026)