There is something I do not understand as I go through various shops owned by associates. You see a lot of machine operators putting a part in the vise, tighten and then beating it down. I just don't get this. I have my own CNC shop and I NEVER do this and I have never done it in over 40 years in machine shop. I'll adjust the vise (Kurt) cut the jaws, put the part in and will work easily within .0005" all day long. I have never had an issue. Beating the parts down has to have an affect on the jaw alignment, ya think? These guys that do this remind me more of blacksmiths, not precision machinists.
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Dead blow hammers and parts in vises
- Thread starter Wild West
- Start date
- Replies 91
- Views 22,087
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
The moving jaw is a few thousandths away from the vise floor. So the moving jaw can be of angle .001 or .002 (or more). That can lift part off the vise floor..The hammer trick can reduce this happening some what but still the off angle can be there....Setting two shims under the part can a the test to know the part is square and tight to the floor.
I like to put a .02 x 1/4 shim on the movable jaw about 3/4 up the part so the part is square to the fixed jaw..but each to his own and if you are having good parts the that is fine...
To see this vise error put in a one inch piece that is a little shorter than the vise is wide but fills the vise to full height or a little higher and tighten. Next take your jo blocks and test the vise width near top and deep to see if there is a difference. better and best vises will have less error.. Too much tightening force can even bend the vise floor..Again better vises have less chance of this.
I like to put a .02 x 1/4 shim on the movable jaw about 3/4 up the part so the part is square to the fixed jaw..but each to his own and if you are having good parts the that is fine...
To see this vise error put in a one inch piece that is a little shorter than the vise is wide but fills the vise to full height or a little higher and tighten. Next take your jo blocks and test the vise width near top and deep to see if there is a difference. better and best vises will have less error.. Too much tightening force can even bend the vise floor..Again better vises have less chance of this.
JNieman
Titanium
- Joined
- Nov 12, 2011
- Location
- Greater St Louis Area
Yup. That, exactly.
I did it back in my younger days because older guys did it, mainly. I thought it was part of 'seating the part' in the vise. I never realized that it wasn't doing shit unless I had the part in crooked to start with. The real solution is to not put the part in there crooked in the first place. It's one thing to give it a couple raps to listen for a "click" that tells you it moved and hit a parallel/jaw, before the vise is really tightened up. It's another to wang on it after the vise is tight. If you can move the part after tightening the vise... what's your vise doing??
Having vises that aren't abused and aren't pieces of junk helps.
metalmagpie
Titanium
- Joined
- May 22, 2006
- Location
- Seattle
If your part is on parallels and the parallels are loose (without tapping) how can the part come out accurately? And how often can you wiggle parallels after you clamp the part they're supporting in your mill vise?
I'm all for soft jaws. But I believe in tapping a part down solidly against the parallels.
metalmagpie
I'm all for soft jaws. But I believe in tapping a part down solidly against the parallels.
metalmagpie
Danny VanVoorn
Titanium
- Joined
- Nov 3, 2002
- Location
- St.Louis, Missouri, USA
The shops I worked in most of my career didn't have Kurt vises, only big old heavy cast iron relics to do the job with. Not complaining but it wasn't possible to set a part on two parallels and have it down on both so the mallet was used to get it done.
Dan
Dan
onecut
Hot Rolled
- Joined
- Jun 27, 2013
- Location
- england-newcastle upon tyne
Depends on the quality of vise and where you work.No doubt a job held in a Kurt wouldnt needed the job tapped down,So I take it you never put a job sitting in the vise on parallels main reason for them is to feel each parallel to see if the job is down .Obviously on older vises the near jaw can have a slight lift in it and pass it onto the job,(Parallels movement)So a tap down with brass knocker would be necessary.So the guys tapping job down probably working on vises that have slight movement on moveable jaw.If you didnt tap the job down on these well used,worn vises you would be producing a lot of scrap
JNieman
Titanium
- Joined
- Nov 12, 2011
- Location
- Greater St Louis Area
I was thinking more of the types of guys who raise the mallet above their head and beat the shit out of the blank in the vise. Not the ones giving a couple reassuring raps from ~6" over the stock piece. At least that's what I imagined. I've seen people hitting shit with a deadblow like they were hammering a nail.
michiganbuck
Diamond
- Joined
- Jun 28, 2012
- Location
- Mt Clemens, Michigan 48035
My best vise is is more like a heavy lay down angle plate..Using a pair of parallel or C Clamps to hold the part..yes for grinding. Near dead zero every time.
Larry Dickman
Titanium
- Joined
- Jan 30, 2014
- Location
- Temecula, Ca
but this is only after they finished beating the living fuck out of the vise handle.
allloutmx
Titanium
- Joined
- Mar 6, 2013
- Location
- Rochester, NY
IMO- it is not malpractice to seat your parts with a hammer but I do agree most people dont have a clue what they are doing when they strike parts with a hammer. Anyone with experience running strip jobs knows you have to seat your parts in the vice on the operation where you take the multiple parts on the strip and make them into singles. Grasping the hammer by the "head" rather than the handle will give you a much better feel for what you are doing and also dampens the rebound of the work piece off the floor of the vice jaw. This all works well when you have adequate clamping pressure and a decent vice.
Seating parts in a vice properly can also provide you with plate work, flat and parallel within .0001"
Seating parts in a vice properly can also provide you with plate work, flat and parallel within .0001"
DavidScott
Diamond
- Joined
- Jul 11, 2012
- Location
- Washington
Depends on many things but I do use a deadblow hammer on the parts when they need them and only as hard as is needed. If you hit too hard it may lift the part. Today the parts are getting tapped down in the fixture and the fixture goes in the vise on parallels with no hammering down. The moving jaw parallel moves but only by a few tenths, which makes no difference for op1 on these parts.
Careful with hammering on things with others watching, monkey see monkey do can get the shit beat out of things.
Careful with hammering on things with others watching, monkey see monkey do can get the shit beat out of things.
Yrs, and then they also hit the vice handle the same way...
Usually they are running a large K&T vertical with a 8" face mill peeling off 1/2" from scaley hot rolled parts fresh off the burn table.
John Welden
Diamond
- Joined
- Mar 21, 2009
- Location
- Seattle
If you part is on parallels AND the bottom of the part is flat, then yes, tapping it down against the parallels is the right thing to do. And tapping it down and testing if the parallel are tight is the right thing to do. Just tapping it down to tap it doesn't do anything. It's easy to tap and not have the part seat down. Key word is tap. Beating the rat fuck out of the part is stupid. 
If the bottom of the part isn't flat, there is no point to tapping/beating it down. If you distort the part and force it down by beating on it, it's just going to spring back when you take it out of the vise.
IF you put a part that is truly flat and square in a vise on parallels, it hardly takes anything to get it to seat. The more wonky the part is, the harder it will be to get to seat.
Here is how to load a part on parallels:
Clean everything
Set part on parallels
tighten vise to proper amount
tap part down
check parallels for tightness
tap more if needed to get the part to seat
Machine part.
Notice there was no step where you go back and retighten the vise to make sure its tight. It was tight the first time.
If the bottom of the part isn't flat, there is no point to tapping/beating it down. If you distort the part and force it down by beating on it, it's just going to spring back when you take it out of the vise.
IF you put a part that is truly flat and square in a vise on parallels, it hardly takes anything to get it to seat. The more wonky the part is, the harder it will be to get to seat.
Here is how to load a part on parallels:
Clean everything
Set part on parallels
tighten vise to proper amount
tap part down
check parallels for tightness
tap more if needed to get the part to seat
Machine part.
Notice there was no step where you go back and retighten the vise to make sure its tight. It was tight the first time.
JS
Stainless
- Joined
- May 5, 2005
- Location
- Republic of Arizonia
(Sarcastically)
I enjoy watching trained monkeys beat the shit out of parts in a vice with a dead blow....
Just like I like watching them fuck around with a neglected milling machine, then bitch that their parts aren't right....
Or they think it's mint and think the factory parts are out....
It isn't rocket science , if you know the machine is wore out compensate for it...
Or the guy , making Bastardized keys and wondering why they all look like a banana....
I enjoy watching trained monkeys beat the shit out of parts in a vice with a dead blow....
Just like I like watching them fuck around with a neglected milling machine, then bitch that their parts aren't right....
Or they think it's mint and think the factory parts are out....
It isn't rocket science , if you know the machine is wore out compensate for it...
Or the guy , making Bastardized keys and wondering why they all look like a banana....
kustomizingkid
Titanium
- Joined
- Aug 2, 2010
- Location
- Minnesota
I was taught to clear all the chips, put the part in, LIGHTLY tighten the handle, easy rap with the hammer and tighten fully... gives the parallels a quick wiggle and move forward if everything looks and feels good. There is a massive difference between a fresh vise and an old haggard pos.
ManualEd
Stainless
- Joined
- Oct 13, 2014
- Location
- Kelowna, Canada
One of the guys I went to school with could never seem to get the part to sit flat against his parallels and get a square cut seating parts with the schools 3 lb dead blow hammer.
The teacher was pretty confused by the new 10 lb dead blow sitting on the guys mill the next day.
The teacher was pretty confused by the new 10 lb dead blow sitting on the guys mill the next day.
"I'll adjust the vise (Kurt) cut the jaws, put the part in and will work easily within .0005" all day long"
What do you mean 'cut the jaws'? Is that some sort of secret machinist lingo? Are you cutting the jaws every time you use the vise? Huh?
What do you mean 'cut the jaws'? Is that some sort of secret machinist lingo? Are you cutting the jaws every time you use the vise? Huh?
Davis In SC
Diamond
- Joined
- Sep 14, 2005
- Location
- South Carolina USA
I make some parts that must be cut flat/square/ parallel, etc.. In that case, I usually grind the stock flat and parallel.. I almost always sweep the part using a Bes-Test .0001 DTI, on an Indicol... Seldom do I find the blank sitting flat, even in a new Kurt 3600 vise. Generally takes some tapping around to get things aligned...
