ISO Thread Chasers

[Conway Bennett]

All,

I cannot find thread chasers for sale, not taps, for frame prep.  Even what park tools sells are taps.  Can someone please direct me to a source?  Thanks in advance!

[Garth]

Taps are also used to chase threads in any bike shop. I have taps for both the derailleur hanger and bottle/rack mounts and have used them to chase the threads with some light oil. For a BB you can make your own chaser if you have a dremel tool and some spare cups from a old cup/cone BB. RJ the bike guy has a video on it. https://www.youtube.com/watch?v=1IrAGP22V34

[Bill Lindsay]

M6x1.0mm and M10x1.0 should be easy to find.  M5x0.8mm probably won't be easy to find in a chaser.  You'd probably need to roll your own or use a tap for M5x0.8mm.  

Bill Lindsay

El Cerrito CA

[Gordon Stam]

You can google "Metric thread restorer kits" and get some reasonably priced options. They are not taps. As Bill said the M5x 0.8 and smaller don't seem to be included. I have such a kit and mine went down to 6x1.0, I think. The problem I've found with the kits is I end up losing the most commonly used size and I end up going and buying a tap to do the job, for not much money. For whatever reason I don't seem taps, maybe because they are bigger.

My kit has both SAE and Metric and is missing the M8x1.25 and the M6x1.00, if it ever had one (I'm pretty sure it did). I'm also missing the 5/16x20 SAE, which size is common on the snowblower I'm restoring. In fact I'm heading down to Ace hardware this afternoon to pick up that particular tap to add to my mostly metric collection. So my thread restorer kit has become somewhat worthless. 

[Gordon Stam]

I meant to say, I don't seem to lose taps.

[Nick Payne]

Do you want to chase and face the bottom bracket shell threads, or just the threads for bottle cage, rack, fender, and derailleur hanger mounts? If only the latter, any decent hardware should be able to sell you M5, M6, and M10 taps. You probably want plug taps - bottoming taps are hard to start if the threads are really filled with paint, and taper taps shouldn't be needed if just cleaning out existing threads.

Icetoolz sell a kit containing M3, M5, M6, and M10 taps, plus LH and RH 9/16" pedal taps (https://www.icetoolz.eu/en/icetoolz-complete-tap-set-with-handle-wring-iron-e158/a5708). Or if you look on Aliexpress, you can find all those sizes pretty cheap, though how long they will last is another matter. You can even find pretty cheap BB taps on Aliexpress - eg https://www.aliexpress.com/item/1005009326101218.html.

Nick Payne