How many in. lbs. of torque for changing blades???

Discussion in 'Lawn Mowing' started by walker-talker, Nov 22, 2004.

  1. walker-talker

    walker-talker LawnSite Platinum Member
    from Midwest
    Messages: 4,771

    Looking for cordless impact wrench and comparing the in. lbs. of torque. So far, the DeWalt DW055K-2 for $219 with free shipping is looking like the winner. Coming in at 1,550 in. lbs. of torque. I think this should be efficient...what do you think?
  2. Blessed 1

    Blessed 1 LawnSite Senior Member
    Messages: 516

    I think that if you use 1/2 that amount of torque you will never get the blades off. I try not to really bare down with my $49.00 electric impact wrench. Even my dealer when installing blades just barely tightens them after the get to the knocking sound and thats a plenty. That Dewalt you are looking at will surely get the job done!
  3. geogunn

    geogunn LawnSite Gold Member
    from TN
    Messages: 3,010

    as for the stregnth of the wrench to torque, I dunno. I use a 1/2 in air ratchet for removal.

    but I use a torque wrench to tighten the blades. 90 ft/lb is recommended but I do 100 ft/lb.

  4. KINGjosh

    KINGjosh LawnSite Senior Member
    Messages: 531

    i just hand tighten it with 2 socket renches
  5. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,699

    To get foot pounds just divide the inch pounds by 12. So you start with 1,550 inch pounds and end up with 129 foot pounds. That should be sufficient.
  6. DennisF

    DennisF LawnSite Bronze Member
    from Florida
    Messages: 1,381

    Don't over-torque the blade bolts. If the manual says 75-80 lbs/ft... that is all the torque that is needed. If you over-torque the bolts, they will stretch which will weaken them and possibly causing them to break. An impact wrench is not necessary for blade bolts. A simple click torque wrench is much more accurate and easier to use.
  7. Smithers

    Smithers LawnSite Silver Member
    Messages: 2,265

    Richard, your formula is correct, but 1550 makes it 125, not 129 ft.lbs as you stated.

    Also, depending on the mower. Exmark says 125
  8. Jackman

    Jackman LawnSite Member
    from Zone
    Messages: 231

    Ive never in 12 years torqued the blade bolts and have had zero problems........ Air gun off, air gun on......
  9. Travis Followell

    Travis Followell LawnSite Silver Member
    from KY
    Messages: 2,206

    We don't torque our bolts either. We use an impact wrench to take them off and an impact to put them on and we've never had a problem either.
  10. walker-talker

    walker-talker LawnSite Platinum Member
    from Midwest
    Messages: 4,771

    Normally I just use the Campbell Hausfield impact wrench that came with the air compressor and it has always worked fine. Doubt if it matters, but they are doubles, but they have a special bracket for's just not two blades laying on top of each other. I might just get buy using a "T" tire iron. I will only have to do this in the field a few times when I am out scalping. Thanks for the post.


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