# What size leveling feet



## Aukai (Mar 11, 2022)

2500lb mill that I'm raising with 6 x 6 .250 wall box tubing. I know weight ratings, but what about foot diameter?


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## 682bear (Mar 11, 2022)

I have my 4000 lb Cincinnatti horizontal sitting on 3 inch diameter leveling feet... 5/8" bolts, with the rubber pads on the bottom.

-Bear


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## Aukai (Mar 11, 2022)

Is that the separate disc that a bolt rests in the dished top?


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## 682bear (Mar 11, 2022)

No, the bolt is connected to the foot with a swivel...










IIRC, they are rated at 1500 lbs each... so 6000 lbs for a set of 4.

-Bear


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## rwm (Mar 11, 2022)

You could do a nice setup with 4 hockey pucks backed by discs of the same diameter.


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## 682bear (Mar 11, 2022)

I stand corrected... they are supposed to be rated at 5000 lbs each... per the online specs.

These are Snaplock LP3 levelling feet, purchased on ebay...

-Bear


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## mksj (Mar 11, 2022)

Might look at S&W leveling feet, I use 1/2" on my mill they are usually rated to 5-6,000 lbs, But I prefer the 5/8 thread size as a bit more meat and heavier threads. I used the 5/8" on my last lathe.

*BSW-3A*


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## woodchucker (Mar 11, 2022)

I made these for an 800lb surface grinder. I am sure they are capable of a 6000lb rating.
I sanded the chamfer/radius on the corners

edit: 3/4 all thread


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## IamNotImportant (Mar 12, 2022)

How do you all feel about making some feet out of 2.5 inch dia brass?


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## rwm (Mar 12, 2022)

Found the hockey pucks:


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## WobblyHand (Mar 12, 2022)

As I found out, regulation hockey pucks seem to deflect a bit too much for my lathe.  I went with four inch steel discs for feet.  However, I have used hockey puck feet for my mill.  They work great there.


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## Aukai (Mar 12, 2022)

Thank you all, I ordered the Snap Lock 3/4 -10 3" base levelers.


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## mickri (Mar 12, 2022)

Instead of focusing on the feet I would look into the strength of the threads.  I am sure that there are engineering tables that give the spec's on what different size threads will support before the threads deform.  It may well be that even fairly small diameter threads will support the weight of the typical machines we use.


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## mickri (Mar 12, 2022)

With nothing pressing this afternoon I decided to research how much force is needed to strip the threads on nuts and bolts. .    Did not find any tables on the force required to strip threads.  One post I read referenced the proof load of nuts as the value at which a given nut size would strip.  Didn't seem to matter whether the load on the nut was pushing the nut or pulling the nut.  That should be easy to find.  Not.  After spending more time than I should have on this all I learned is that the calculations are mind boggling to a non engineer and that a standard size nut for a given bolt is stronger than the bolt.  Bolts are referenced by tensile strength.  There are charts for the tensile strength of bolts.  A 1/4-20 has a tensile strength of 1750 lb.  A 3/4-10 has a tensile strength of 15,200 lb.  This a for a cheapy grade 2 bolt.  The clamping force is 75% of the tensile strength.

As best as I can tell the bolts you guys are using are way overkill for the loads applied to the bolts.  Now there may be other factors that I am unaware of the require larger bolts and nuts.

I did this because I am thinking of using nuts on threaded rod to level my lathe instead of shims.


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## IamNotImportant (Mar 12, 2022)

mickri said:


> With nothing pressing this afternoon I decided to research how much force is needed to strip the threads on nuts and bolts. .    Did not find any tables on the force required to strip threads.  One post I read referenced the proof load of nuts as the value at which a given nut size would strip.  Didn't seem to matter whether the load on the nut was pushing the nut or pulling the nut.  That should be easy to find.  Not.  After spending more time than I should have on this all I learned is that the calculations are mind boggling to a non engineer and that a standard size nut for a given bolt is stronger than the bolt.  Bolts are referenced by tensile strength.  There are charts for the tensile strength of bolts.  A 1/4-20 has a tensile strength of 1750 lb.  A 3/4-10 has a tensile strength of 15,200 lb.  This a for a cheapy grade 2 bolt.  The clamping force is 75% of the tensile strength.
> 
> As best as I can tell the bolts you guys are using are way overkill for the loads applied to the bolts.  Now there may be other factors that I am unaware of the require larger bolts and nuts.
> 
> I did this because I am thinking of using nuts on threaded rod to level my lathe instead of shims.


the bolts needed for my lathe are 10mm x 1.5, seems that would be sufficient


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## Aukai (Mar 12, 2022)

Thank you for taking the time on that. I also wish to spread the load on the .250 wall 6 x 6 riser.


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## 682bear (Mar 12, 2022)

mickri said:


> With nothing pressing this afternoon I decided to research how much force is needed to strip the threads on nuts and bolts. .    Did not find any tables on the force required to strip threads.  One post I read referenced the proof load of nuts as the value at which a given nut size would strip.  Didn't seem to matter whether the load on the nut was pushing the nut or pulling the nut.  That should be easy to find.  Not.  After spending more time than I should have on this all I learned is that the calculations are mind boggling to a non engineer and that a standard size nut for a given bolt is stronger than the bolt.  Bolts are referenced by tensile strength.  There are charts for the tensile strength of bolts.  A 1/4-20 has a tensile strength of 1750 lb.  A 3/4-10 has a tensile strength of 15,200 lb.  This a for a cheapy grade 2 bolt.  The clamping force is 75% of the tensile strength.
> 
> As best as I can tell the bolts you guys are using are way overkill for the loads applied to the bolts.  Now there may be other factors that I am unaware of the require larger bolts and nuts.
> 
> I did this because I am thinking of using nuts on threaded rod to level my lathe instead of shims.


The bolt sizes are overkill... but the bolts need to somewhat fit the holes in the machine base, also. I ordered the feet with 5/8-11 studs, because the holes in the base of the machine are clearanced for a 5/8 bolt...

Also, while four 1/4" bolts may have enough tensile strength, putting that much weight... especially unbalanced weight... would tend to bend the bolts.

The shear strength is much weaker...

When considering any unbalanced loads, inertia loads, and the overall rigidity of the machine setup, overkill is your friend. I prefer to use the biggest bolts that will fit the holes in the base...

-Bear


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## Aukai (Mar 12, 2022)

I'm not sure if my bolt holes in the base were 23/32 or metricI opened them up to 3/4"


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## stupoty (Mar 13, 2022)

mickri said:


> With nothing pressing this afternoon I decided to research how much force is needed to strip the threads on nuts and bolts. .    Did not find any tables on the force required to strip threads.  One post I read referenced the proof load of nuts as the value at which a given nut size would strip.  Didn't seem to matter whether the load on the nut was pushing the nut or pulling the nut.  That should be easy to find.  Not.  After spending more time than I should have on this all I learned is that the calculations are mind boggling to a non engineer and that a standard size nut for a given bolt is stronger than the bolt.  Bolts are referenced by tensile strength.  There are charts for the tensile strength of bolts.  A 1/4-20 has a tensile strength of 1750 lb.  A 3/4-10 has a tensile strength of 15,200 lb.  This a for a cheapy grade 2 bolt.  The clamping force is 75% of the tensile strength.
> 
> As best as I can tell the bolts you guys are using are way overkill for the loads applied to the bolts.  Now there may be other factors that I am unaware of the require larger bolts and nuts.
> 
> I did this because I am thinking of using nuts on threaded rod to level my lathe instead of shims.



I have some 12mm studding leveling my drill press stand , the diameter is probably to stop them bending more than taking the load.  I made some simple nut and bolt style leveling feet for my lathe , they are 1inch 8tpi but it's only about 550kg.

Stu


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## mickri (Mar 13, 2022)

The manual for my lathe doesn't specify the size of the bolts to mount the lathe on the bed.  Just says use supplied screws.  My lathe weighs around 350 pounds.  The motor and its mounting bracket is separate from the lathe.  The lathe by itself probably weighs around 275 pounds.  I can pick up either end of the lathe.  My current mounting bolts are 7/16.  All the bolts do is hold the lathe to the bench.  Don't support the weight of the lathe.  I think that 1/2 is the largest bolt that will fit through the mounting holes.  I plan to make threaded washers (wrong term??) as thick as a standard size nut.   Flange nuts would also work. The bolt will come up through the bench top.  A threaded washer will be screwed down to hold the bolt in place.  Another threaded washer will be screwed onto the bolt.  The lathe will sit on this washer.  Then there will be a nut that holds the lathe against the threaded washer.  Move the threaded washer that the lathe sits on to remove any twist in the bed.  Then tighten the nut to hold everything in place.  That's the plan so far.


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## 682bear (Mar 13, 2022)

mickri said:


> The manual for my lathe doesn't specify the size of the bolts to mount the lathe on the bed.  Just says use supplied screws.  My lathe weighs around 350 pounds.  The motor and its mounting bracket is separate from the lathe.  The lathe by itself probably weighs around 275 pounds.  I can pick up either end of the lathe.  My current mounting bolts are 7/16.  All the bolts do is hold the lathe to the bench.  Don't support the weight of the lathe.  I think that 1/2 is the largest bolt that will fit through the mounting holes.  I plan to make threaded washers (wrong term??) as thick as a standard size nut.   Flange nuts would also work. The bolt will come up through the bench top.  A threaded washer will be screwed down to hold the bolt in place.  Another threaded washer will be screwed onto the bolt.  The lathe will sit on this washer.  Then there will be a nut that holds the lathe against the threaded washer.  Move the threaded washer that the lathe sits on to remove any twist in the bed.  Then tighten the nut to hold everything in place.  That's the plan so far.




I would consider that to be a good plan...

-Bear


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## akjeff (Mar 13, 2022)

mickri said:


> With nothing pressing this afternoon I decided to research how much force is needed to strip the threads on nuts and bolts. .    Did not find any tables on the force required to strip threads.  One post I read referenced the proof load of nuts as the value at which a given nut size would strip.  Didn't seem to matter whether the load on the nut was pushing the nut or pulling the nut.  That should be easy to find.  Not.  After spending more time than I should have on this all I learned is that the calculations are mind boggling to a non engineer and that a standard size nut for a given bolt is stronger than the bolt.  Bolts are referenced by tensile strength.  There are charts for the tensile strength of bolts.  A 1/4-20 has a tensile strength of 1750 lb.  A 3/4-10 has a tensile strength of 15,200 lb.  This a for a cheapy grade 2 bolt.  The clamping force is 75% of the tensile strength.
> 
> As best as I can tell the bolts you guys are using are way overkill for the loads applied to the bolts.  Now there may be other factors that I am unaware of the require larger bolts and nuts.
> 
> I did this because I am thinking of using nuts on threaded rod to level my lathe instead of shims.


Great info, but tensile strength is only part of the picture. For one, I would fill the hole with the largest fastener that will fit it, just to cut down on play/slop, and if you live in an area with even mild seismic activity, then there's shearing forces that may make what is "overkill" in a perfect world, become "sufficient". Even something as small as the bolt not being perfectly perpendicular to the load can derate it significantly. I'm a big fan of overkill.


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## Aukai (Mar 24, 2022)

I got the 6 x 6 cut, and the leveling feet came, but no studs. I thought when I ordered it was included, I sent an email to find out.


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## Al 1 (Mar 24, 2022)

3000 lb. concrete should take 3000 lb. per square inch.   Al.


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## usamech (Mar 26, 2022)

Hmmm... so my all-thread, 1-1/8" diameter adjusters are a little over-kill for an 1100lb Clausing (first lathe) I have yet to get?   I'm new to even being a novice, and can't wrap my head around how a 5/8" diameter bolt can support that much weight/mass, especially absorbing vibration, etc.?  

I'll have to figure out how to put a good radius on the end and dish or dimple a pad for it to sit on.  I press-pinned nuts on all-thread as bolt heads.  I bet somebody here knows...., but it's too early to post that question since I don't even have it yet.


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## WobblyHand (Mar 26, 2022)

usamech said:


> Hmmm... so my all-thread, 1-1/8" diameter adjusters are a little over-kill for an 1100lb Clausing (first lathe) I have yet to get?   I'm new to even being a novice, and can't wrap my head around how a 5/8" diameter bolt can support that much weight/mass, especially absorbing vibration, etc.?
> 
> I'll have to figure out how to put a good radius on the end and dish or dimple a pad for it to sit on.  I press-pinned nuts on all-thread as bolt heads.  I bet somebody here knows...., but it's too early to post that question since I don't even have it yet.
> 
> ...


When I asked the very same question, not all that long ago, I was advised to make an obtuse angle in the end of the bolt head and make a matching dimple in the plate.  If I recall correctly I made a 140 degree angle.  I was told not to bother with making a spherical end as there was no real benefit.  I can report it works fine.


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## NC Rick (Mar 26, 2022)

Al 1 said:


> 3000 lb. concrete should take 3000 lb. per square inch.   Al.


What of vibration and time? Concrete thickness and soil conditions under it?  I seem to have tiny crack webs all around my lathe.  It is maybe 2500 lbs siting of 6, 2” diameter steel disks about 5/8” thick.  I think about these things too much.


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## rabler (Mar 26, 2022)

NC Rick said:


> What of vibration and time? Concrete thickness and soil conditions under it?  I seem to have tiny crack webs all around my lathe.  It is maybe 2500 lbs siting of 6, 2” diameter steel disks about 5/8” thick.  I think about these things too much.


One of my concerns is that I doubt steel on concrete is likely to give a uniform pressure distribution.  Seems like a sheet of cheap self adhesive vinyl tile or similar may make a significant difference in that distribution and absorb some of the vibration without being too soft.  I’m thinking about a couple of 8000lb machines in particular.


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