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Thread: To Pound or Not to Pound a part into the vise so it seats good ???

  1. #1

    Default To Pound or Not to Pound a part into the vise so it seats good ???

    Hello all, Newb here a with puzzling question.

    I've seen people pounding parts down into their vise on top of their parallels etc., and wonder if they're not doing more damage than good by pounding parts in with a dead blow or other type of hammer?

    I've tried this method with mixed results and I have a brand new Kurt vise.

    My vise was not bought as an intended anvil.

  2. #2
    Join Date
    Dec 2008
    Kendal, On


    you are overthinking this exponentially. A tap or two with a dead blow to seat a part wont wear out, or a have a negative effect on anything but your arm.

    Using a rubber hammer, can have a negative effect by "bouncing" the part back up. Big chunk of brass, or bronze also works to. But realistically, thousands of parts are pounded into vises on a daily basis all round the world with no ill effect. Pound away.

  3. #3
    Join Date
    Aug 2013
    Southeast TN, USA


    Even a new Kurt will typically rise the part up somewhat. A firm tap will seat a square part down on parallels, without skewing the jaws to make it so.
    Not to mention... Y'know, it's 80 pounds of USA (hopefully) cast iron, you won't hurt it with a pound-and-a-half plastic hammer.

    BUT - if you don't get the part seated with a firm tap, you have a squareness problem. Don't keep beating! Either you have something, grit, chip, etc. under your part, or a burr, or the thing just ain't square. Granted, that may be assuming your vise isn't warped, or hard jaws are properly square relative to the vise bed.

    If you don't pound it and seat it on the parallels, and you machine a feature on the top face, it will be out of parallel with the bottom - but, it should be square with the sides in the vise. On the other hand, if you pound it until it seats, you may force the jaws open slightly, which will make the bottom parallel - but the sides out of square with the top!

    So... for the TL;DR folks out there... if your part is not out of square or burred, or swarf or other dirt is not on your part or parallels, it should seat easily, with a couple of firm taps. Raising your hammer above your head is too much.

    Edit: I'll add, it must be a deadblow hammer, or as said above, a heavy metal. A solid rubber or plastic hammer will bounce, and not do much to your part at all.

    And also, thought I would mention grinding vises. Typically you would not tap parts into a grinding vise, but then, you are working with both part and workholding surfaces ground to a much higher degree of precision, as well as not having the "in-between" of the hard jaws on a mill vise.
    Last edited by TN Pat; 12-01-2016 at 09:06 PM.

  4. #4
    Join Date
    Aug 2016


    The vise is not an anvil, but it is built to take a fair bit of abuse. Milling can be a good deal of load and shock.

    Light to moderate impact is the appropriate way to seat things, and won't hurt the vise or parallels. Whaling away like a chimp, on the other hand, will beat the precision out of the tool. You want to strike with enough force to break friction and seat the part, but no more. Feel in from the light hit end, and, over little time, you get the feel for how hard to hit. Soft face,dead blow, tools give control without marring the part being hit.

  5. #5
    Join Date
    Dec 2015
    Chilliwack, BC, Canada


    I think if it as more of a "tap" than "driving". And the vise and machine the vise is mounted on is not an anvil so I don't wind up and treat it as such. TAPPING a work piece down onto the parallels or other spacer is intended to ensure that the part is sitting level and did not rise up from the movable jaw and come to rest at some odd skewed angle. It's not to forge the part into place.

    Along with this is the skill of using a suitable amount of clamping force for the sort of cut being made. My milling vise at the moment and for some years now uses a piece of 3/8" drill rod that is roughly 5" long. And i've never had to "gorilla" that short bar to hold what needs holding. I tend to tighten half to 2/3's to what I want, tap the work down back onto the spacer so I know it's "flat" then tighten that last little bit. The spacer or parallels remain tight and I don't need any sort of overhand whack on the work piece. In fact the old lead 5lb scuba weight I use easily seats the part with only a few inches long stroke of a tap used with more of a flick of the wrist.

    Now this is not to say that a nearly over the shoulder blow isn't required in the bigger commercial setups. But for most home shop use it's wiser and smarter to sneak up on what is needed. And generally I'd say that there's no need to reform your new Kurt with a blacksmith hammer like blow. If you need that much you're doing something wrong.

    A little last side comment. It's not a bad form to actually check to see if the parallels or other spacer is loose or not. If it's tight, which you SHOULD get with a Kurt style vise, then there's no need for driving it down. If it's not tight? Then tap it down prior to the final tensioning. I've never found that my spacers or parallels were made loose from the last 1/3 to 1/4 snugging down. It all happens in the first part.
    Last edited by BCRider; 12-01-2016 at 09:16 PM.

  6. #6


    In this video at 1:10, I don't know I was thinking it looked a bit hard to me.

  7. #7
    Join Date
    Jan 2009
    Nordland, WA


    I have a 1 lb. lead ingot I use to tap on parts in the shop. Mill vise, lathe, etc. I have never in my life needed to use anything more in my own shop.

    We're not talking big stuff here either!!

    1973 SB 10K .
    BenchMaster mill.

  8. #8
    Join Date
    Nov 2007
    Woodinville, WA


    I use a small brass faced hammer... to TAP the items into position. It's all in the wrist... TAP it just right and it seats.

  9. #9
    Join Date
    Nov 2002
    Kenosha, not the pass the other one


    If you have a problem with this issue this one solution
    You don't need high buck Starretts. I've made probably 8 sets in the last 40 odd years. In fact if they are soft you can cut into them if need be. Properly used they will nail the down like it is clamped down. Can be used singlely or in pairs. I've got both hardened and soft in my box right now
    Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

  10. #10
    Join Date
    May 2007
    Live Oak, TEXAS


    I worked next to a big dummy that would absolutely WAIL on his poor vise full-force.
    WHAP!! WHAP!!! WHAP!!! WHAP!! WHAP!!! WHAP!!!
    Wailing on a part is pointless.
    One good TAP is enough.
    Even if a part is "Square", it will only make contact with the three highest points, just like a 3-legged stool.
    Because of this, one parallel will always be a little looser than the other one.
    The "Square" part will always be in contact with the two vise jaws, and one of the parallels.
    Last edited by KiddZimaHater; 12-01-2016 at 10:41 PM.

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