So i was cutting wood and noticed the shaft was slipping on the blade. So i took off the blade and put it back on making sure it was tight and it stalled so i loosened the bolt a little bit it stalled less then i loosened it more and it started slipping again i don't know what it could be.

(I have a craftsman 5 1/2 inch 4/5 hp circular saw #H9179 and it is one of the older corded models)

Thank You

  • I tried to look that up but could not find a photo many of my saws have a diamond shaped knock out my son tried to use one with out punching the knockout and it would barely cut. He almost ruined the arbor before asking me. So if it should have a knockout that could be your problem or you may have lost the correct washer that has flats that mate with the arbor on 1 side and or the blade is loose even a dull blade will burn through and not slip if tight.
    – Ed Beal
    Commented Dec 29, 2017 at 0:28
  • .... and one of the older corded models ...... what do you mean and ? are you talking about two saws?
    – jsotola
    Commented Dec 29, 2017 at 3:36
  • @EdBeal, the diamond shaped knockout should only be removed if the machine has a diamond shaped arbor
    – jsotola
    Commented Dec 29, 2017 at 3:43
  • you may be missing a washer or spacer that goes between the blade and the motor. the blade should be sandwiched between two washers. ... make sure that the washers are correctly installed.
    – jsotola
    Commented Dec 29, 2017 at 3:48
  • As I said it was that or the washer that mates to the arbor.
    – Ed Beal
    Commented Dec 29, 2017 at 13:12

3 Answers 3


Why does my circular saw shaft spin and blade does not?

Because you loosened the nut or bolt holding the blade to the shaft.

it stalled so [I] loosened the bolt a little

It would probably be more appropriate to ...

  • sharpen the blade or
  • cut more slowly or
  • make sure the kerf isn't closing onto the blade due to ...
    • poorly supported workpiece
    • stresses in wood

The nut's only job is to hold the blade. If you loosen it, then it can't do that job. If your saw is stalling, then either the blade is dull, you are pushing the saw too fast, or the motor is weak/tired. I also suppose it could be a voltage problem.

  • The saw stalled because the bolt was too tight then i loosened it and it slipped i wasn't cutting wood at that point just troubleshooting
    – SGREY
    Commented Dec 29, 2017 at 0:16
  • you should edit the question to clarify how it stalled.
    – agentp
    Commented Dec 29, 2017 at 0:49

The diamond shape knock-out on the 7-1/4" blade is designed to inter-lock with the diamond shaped protrusion on the arbor of portable circular saws. This takes the load off the shaft bolt and washer. All they have to do now is hold the blade firmly in place on this diamond. This design allows for much tighter tolerance. No space is required behind the blade for a second wrench for back pressure.

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