# Lufkin Holddowns. How Are They Used?



## Wrecks (Mar 31, 2015)

I sort of collect old Lufkin tools and picked these up off Ebay a while back. The thing is, I like to use the tools I buy and I can't figure out how these things are used. Can someone explain?

Thanks.


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## machinistmarty (Mar 31, 2015)

Those holddowns are great! I have a set of starrets and use them all the time.  They put downward pressure on the part and holds it down to the bottom of the vice.  It's a great way to square up steel. Dont be afraid to take cuts either, The holding force will surprize you. You can use them with equal sets of parallels to get clearence underthe part to drill tap etc... Just put your part in the vice with a holddown on either side and clamp.  I always lightly tap the part down, but the slight angle these clamps are ground at, do that for you.  I use them when im flycutting to squre up parts.


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## Wrecks (Mar 31, 2015)

machinistmarty said:


> Those holddowns are great! I have a set of starrets and use them all the time.  They put downward pressure on the part and holds it down to the bottom of the vice.  It's a great way to square up steel. Dont be afraid to take cuts either, The holding force will surprize you. You can use them with equal sets of parallels to get clearence underthe part to drill tap etc... Just put your part in the vice with a holddown on either side and clamp.  I always lightly tap the part down, but the slight angle these clamps are ground at, do that for you.  I use them when im flycutting to squre up parts.



How are they oriented in the vise? Which side is against the part and which side is against the jaws?


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## awander (Mar 31, 2015)

The "pointy side" goes against the part.

The "long flat side" with the small relief (next to the "pointy side" goes down.

The "long angled side" goes up.

The "1/4" or so wide" flat side goes against the vise jaw.

These are really good for holding thin panels.


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## Wrecks (Mar 31, 2015)

awander said:


> The "pointy side" goes against the part.
> 
> The "long flat side" with the small relief (next to the "pointy side" goes down.
> 
> ...



This is great! I can't count the times I've needed something like this and didn't know I had it. I'd have never guessed they were for use in the vise. I've googled them several times and always come up empty.

Thanks!


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## hman (Mar 31, 2015)

Rick Sparber (a member here) has a good write-up on mill vises, which includes a description of how those hold-downs are used.  I'll "take his name in vain" and give you the URL:
http://rick.sparber.org/Articles/sj/sj6.pdf


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## machinistmarty (Mar 31, 2015)

Glad I could help. Awanders discription of how their used is spot on. Great article h-man, I had seen it b4 but my old memory fails me at times.


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## Kevinb71 (Apr 1, 2015)

Call me slow, but I can't quite picture how those would work with thin panels. Thicker parts I get.


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## Bill C. (Apr 1, 2015)

Thanks guys I never seen them before.  I have used a slightly different version for surface grinding years ago.


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## machinistmarty (Apr 1, 2015)

I personally have never used them on amything real thin.  Mostly to square up and hold parts down in the vice. I use them to make bastard keys all the time.


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## awander (Apr 1, 2015)

Yeah, they are quite useful.

I have never seen an illustration showing how to use them in any of the old tool catalogs. Just for grins I searched on Starrett's website, for 20 minutes, without finding them, until I hit the "magic" search term. Evidently "hold down" or "holddown" is not correct, but "hold-down" is! They are still available, the #54, but still no illustration of how to use them.

I know it took me a while to figure it out....


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## awander (Apr 1, 2015)

I guess it depends on what you call thin. I was using these yesterday on a 1/8" thick aluminum panel. I consider 1/8" pretty thin.

I think maybe down to 1/16" aluminum, these clamps would work. Thinner if it was steel.


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## george wilson (Apr 1, 2015)

I have a few sets from 2" long to the more usual 6" long. I have even used mine to hold down 1/32" thick brass sheet when helping my wife to make master models for jewelry making. You obviously don't squeeze thin material real hard. Yet,the hold downs have held the brass snugly enough to allow milling with small cutters and light cuts. 

If I need more strength,I super glue the parts down,and warm them to get them loose afterwards.


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## machinistmarty (Apr 1, 2015)

Heres a 4 inch set in use making an obsolete master cylinder.
	

		
			
		

		
	



	

		
			
		

		
	
  Notice I have 2 sets of parallels under the part. One thick set under the part and the hold downs and a thin set to support the vice side of the hold downs b4 clamping down.


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## george wilson (Apr 2, 2015)

But,why would you use hold downs in that application? To make sure the block of aluminum was pressed down against the parallels? I do that with a few swats of a soft faced dead blow hammer,using the vise jaws to hold the work against the parallels. Seems more secure to me.


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## chips&more (Apr 2, 2015)

I have at least one pair of those things and can say that I have never used them in 50 years. About 50 years ago I vaguely remember seeing a machinist using them on a shaper set-up. In today’s world with the anglock feature, soft jaws that you can custom form and other tricks. I think the said hold downs for the vise are just fun to talk about. If I machine something thin, I super glue it down and then boil it in water after to remove. Or may use my vacuum plate, double sided tape, or my magnetic plate. Please note that all these methods are not foolproof and stuff could start to fly around, so please be careful…Good Luck, Dave.


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## machinistmarty (Apr 2, 2015)

That is 4140 George. I probably could have just used the parallels. It was crucial the bores were square with the top and sides.  I have had very good success with hold downs. Even with the Kurt vice parallism is hard to obtain. The two large bores connected with orifice holes bored crossways in the block. The three small holes go through to mount it. I made 3 of these and they worked great.  I almost used soft jaws but the hold downs worked great


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## chips&more (Apr 2, 2015)

machinistmarty said:


> That is 4140 George. I probably could have just used the parallels. It was crucial the bores were square with the top and sides.  I have had very good success with hold downs. Even with the Kurt vice parallism is hard to obtain. The two large bores connected with orifice holes bored crossways in the block. The three small holes go through to mount it. I made 3 of these and they worked great.  I almost used soft jaws but the hold downs worked great



I too on occasion have had problems with the vise not holding square/parallel. And using a Kurt anglock to boot? To solve the problem, I did not have the movable jaw touching the part. Instead, I placed a piece of round stock in the horizontal position between the moveable jaw and the part. And tapped the part down with a lead hammer. After that, the problem went away…Good Luck, Dave.


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## machinistmarty (Apr 3, 2015)

Dave, I also have solved the problem at times by using aluminum welding rod on the movable jaw.  The point of my post was to show the hold downs in use. Not to suggest that anyone use them in the manner that I did. But at no time when I used them did the parts move. Milling ,Drilling, fly cutting ,boring, or lapping. A Kurt vice is in itself an incredible piece of machinery. I am pretty much a blacksmith machinist. George is an artist. All that being said, not everyone or every shop has surface grinders etc. The entire piece was made with basic tools and the accuracy was incredible. They worked and I didnt have to take the time to make soft jaws for the job. I have made numerous bastard keys and stepped keys using hold downs. They work. Thats the only point i was trying to make. If Wrecks got something from this, Thats all that matters.


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## machinistmarty (Apr 3, 2015)

The only thing I have ever seen two machinist agree upon is........ The third one is doing it wrong!


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## hman (Apr 3, 2015)

machinistmarty said:


> The only thing I have ever seen two machinist agree upon is........ The third one is doing it wrong!



OMG!!  ROTFLMAO!!  Ya done made my day, Marty!  Thanks!


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## machinistmarty (Apr 3, 2015)

Glad I made you smile!


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## EmilioG (Apr 25, 2017)

Wouldn't steel balls with a ground flat or round aluminum wire/rods do the same thing as the Hold-Downs?


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## francist (Apr 25, 2017)

No. The rear angle of the hold-down (that is the thicker of the two edges) is ground such that it is not 90 degrees. In use, the slight more-than-90 angle on that thicker edge causes the hold-down to want to angle down towards the bed of the vise, and in doing so it takes the part with it. When you use two hold-downs with the part in between, they draw the part flat down to the vise bed as well as pinch it between the jaws.

-frank


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## george wilson (Apr 26, 2017)

Exactly correct,francist. I have hold downs down to 2" long. The 2" ones may have been shop made by a GOOD tool maker. They are usually 6" long. The 6" kurt vises have flat areas about 2"wide on either side of the center area,which is where the screw lives.

I have used that little 2" wide area to hold small jewelry master models. Just as the jaws of the vise reach the thick side of the hold downs,they begin to cock up as the vise is tightened. The thin side,which is against the work piece,rotates downwards,pulling the work piece down against the vise. Your work piece needs to have 2 parallel sides,opposite each other. If mine doesn't,I just super glue them down,as I mentioned before. Since I'm only using end mills about 1/32" wide,maybe up to 1/8" wide,the glue is plenty strong enough. I never have had a glued workpiece come loose.

To be functional,your hold downs need to be crisp and accurately ground so that the thin side has sharp edges so they grasp the work as it is being pulled downwards. This has to be done in a surface grinder,or a tool and cutter grinder. I have never seen a pair of hold downs that had dulled corners. They aren't a tool that is used often,and are made of good tool steel that is hardened.


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## Silverbullet (Apr 26, 2017)

They also let you mill down that side between the jaw and the material. There not utilized much anymore in the old shops every machinist had several in different sizes. We made sets in vokie when I went in the early 70s. Our shop teachers had us make tools for grades we had two tool & die ,  + machine shop. 
 The tool shop had the heat treatment room and grinding room. Even  cylindrical grinder . We made some Kool items , a gear case with sliding mesh to shift gears. Splines and gears all made by students. Class projects we all got to keep the tools we built.


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## woodchucker (Apr 26, 2017)

I wish I could make out the pics better. For some reason, I just don't see how they are working. Someone have a better pic?


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## francist (Apr 26, 2017)

Does this help? Not the best, agreed, but what I could come up with at the moment. I know it's a bit hard to get your head around how they're oriented, but once you get the theory they make perfect sense. 

This was excerpted from one of my shaper references, and that's where I see them mostly. I suspect they may have dropped out of favour at the same time as the shaper did? They don't seem to be commonly referenced in modern milling machine practise. Just guessing at that though. Maybe some of the more experienced guys who worked in shops as shapers went out could comment.

-frank


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## woodchucker (Apr 26, 2017)

perfect. Thank you.


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