M12 Subcompact 3450-20 Impact Driver Auto Anvil Swap
I've had the M12 Subcompact drill & driver set for about 7 months now. Finally got tired of the basic non-auto (insertion) chuck on the impact driver. I have only seen people ask about it but haven't seen anyone actually do the swap. I'm pretty sure I'm the first one to do it.
Took me this long to finally try cause I didn't have that much hope for being a simple drop in part swap & I was right. Luckily I didn't have to modify much. Parts list for the 3450-20 doesn't list much, not many parts you can buy for it which is no surprise to me these days for MW.
I used the anvil from the M12 Fuel gen3 impact driver 3453-20. I bought all the parts for the complete anvil & chuck assy but in the end all that is needed is the anvil & the retention spring for the locking ball. Can even reuse the original 3.5mm ball.
The M12 Fuel anvil "ears" or whatever they're called are longer than the Subcompact. All that is needed is to reduce the diameter/length. Yeah I know, easier said than done if you don't have a lathe. And of course the anvil is hardened and it's a heavy interrupted cut so carbide is probably a must.
Posted Dec 8, 2025, 3:41 AM UTC