Socket head flat screw sizing relative to material thickness

[mike93lx]

I need to bolt some casters to steel angle for a project and and trying to determine bolt sizing.

In order to have the heads flush, I am planning to use countersunk, flat head screws



Material thickness isn't set, but I was thinking 1/4" steel.

3/8 screws have a head height of 0.234" and 5/16 are 0.198"

This made me wonder if there is a relationship of head height to material thickness that should be maintained when using a countersunk screw. In this case, neither are carrying any load other than the clamping force to hold the caster in place, so let's assume either size is adequate.

Thanks

 

[PCustoms]

The head height should be slightly less then the material thickness, or else you're going to have (one would think) fairly obvious problems. When someone goofs, there are undercut countersunk screws available.

How are you setting this up? I can't see where the countersunk screws has an advantage. If coming down through the plate and then caster, backed up with nuts, can you tap the plate?

 

[no704]

I’ve always just used standard hex bolts with lock washers for casters. But you can get under cut flat heads if needed.

 

[mike93lx]

The head height should be slightly less then the material thickness, or else you're going to have (one would think) fairly obvious problems. When someone goofs, there are undercut countersunk screws available.

How are you setting this up? I can't see where the countersunk screws has an advantage. If coming down through the plate and then caster, backed up with nuts, can you tap the plate?

Tapping the plate hadn't crossed my mind.

I need to move a 6klb wood structure on a smooth floor. Plan is to lift it up enough to get the caster/angle iron assembly underneath, attach the angle to the side (just to hold it in place) then lower it down on the casters. I want the inside of the angle iron to bear directly on the bottom of the structure, so I am avoiding hex head bolts. Tapping the angle then grinding the bolts flush will work but is probably a wash compared to cutting countersink and the countersink approach is simpler.

Using angle allows me to mount the caster with out having to bolt it to the underside.

Other option is renting a couple pallet jacks, but this way, I end up with some heavy duty casters to use down the road and i don't have to watch the clock on a rental

 

[PCustoms]

Tapping the plate hadn't crossed my mind.

I need to move a 6klb wood structure on a shoot floor. Plan is to lift it up enough to get the caster/angle iron assembly underneath, attach the angle to the side (just to hold it in place) then lower it down on the casters. I want the leg to bear directly on the bottom of the structure, so I wanted to avoid hex head bolts. Tapping the angle then grinding the bolts flush will work but is probably a wash compared to cutting countersinks.

Using angle allows me to mount the caster with out having to bolt it to the underside.

Other option is renting a couple pallet jacks, but this way, I end up with some heavy duty casters to use down the road and i don't have to watch the clock on a rental

I'm having deja vu, you moving your tornado shelter again?

 

[mike93lx]

I'm having deja vu, you moving your tornado shelter again?

Not again, but yes, thats it. Coming back to the project and hoping to execute this winter.

I was thinking wheel dollies, but I want a "fab" project to work on, and this was an idea I had for making it mobile.

 

[larry4406]

Not again, but yes, thats it. Coming back to the project and hoping to execute this winter.

I was thinking wheel dollies, but I want a "fab" project to work on, and this was an idea I had for making it mobile.

We need the thread “Mike moves the Safe House”. We like pictures.

 

[mike93lx]

We need the thread “Mike moves the Safe House”. We like pictures.

. I'll post a thread, don't worry. Including using my quickjacks to lift it up.

 

[PCustoms]

Not again, but yes, thats it. Coming back to the project and hoping to execute this winter.

I was thinking wheel dollies, but I want a "fab" project to work on, and this was an idea I had for making it mobile.

A real project would be making 4 machinery skates and a turnbar. You have a lathe, right?

Personally I'd use 3/8" plate, drilled and tapped. Get some 7/16" long bolts, should be perfect once you bolt the caster on. May even need 1/2" long with a washer...

Countersinking 16 holes by hand or on a drill press just doesn't meet my idea of fun. Ymmv

 

[mike93lx]

You have a lathe, right?

Yeah, it's right next to my telehandler... ****, I should just use that

The thing I liked about angle is being able to attach it. My floor is flat pretty flat and very smooth, but I'd prefer to not run the risk of a skate sliding out

I'm over thinking the bolt heads and could just run regular hex heads. They'll dig into the wood, but it won't matter at all

 

[PCustoms]

The thing I liked about angle is being able to attach it. My floor is flat pretty flat and very smooth, but I'd prefer to not run the risk of a skate sliding out

Got a sketch or a mockup?

I sort of remember talking about it. Unless I'm way off I don't see why the angle would prevent tapping for the bolts..

Though there is a bit of irony that you want to be so careful with the caster boots digging in while you screw/bolt the angle on!

 

[mike93lx]

Got a sketch or a mockup?

I sort of remember talking about it. Unless I'm way off I don't see why the angle would prevent tapping for the bolts..

Though there is a bit of irony that you want to be so careful with the caster boots digging in while you screw/bolt the angle on!

Nothing right now, but I'm not buying or ordering any supply's just yet. I'll see if I can do something this week.

I'm good with just hex bolts now. It wasn't so much about digging in, and More about maximizing contact. This is the heaviest and largest thing I've had to move and I have no one to help in person that's done this before, so just thinking things through.

The idea is to take a ~6" piece of 4x4x1/4 angle, mount a single caster to one leg with 3/8 bolts, and drill two 1/4" holes in the other leg for Grk structural screws. Jack up the shelter and set it down on some cribbing. Then place the skate assemblies under the walls and screw them on. Jack it up, remove cribbing and set it down on the skates.

Thinking something like 8 of these. Lots of no name versions of them, rated at between 1100-1800 each. I'm skeptical of the rating, but think/hope it will be fine.
W B D WEIBIDA 4-inch Heavy Duty Plate Swivel Caster Wheel, Low Gravity Center Design Black Caster Wheels with Brake Load Capacity 7000lb, Durable & Quiet & Sturdy Nylon Wheels for Industrial, Set of 4 https://www.amazon.com/dp/B0CM3B2TKK?tag=atomicindus08-20

I'll need to cut the anchor rods flush with the floor (5/8" threaded rod, epoxied into the floor), which I am planning to do with a sawzall. They're all shorter than the casters, so I should be able to cut them after I get it out of the way.

 

[PCustoms]

Flat leg under the wall, upright leg up the side?

It will work, realistically probably overkill. Don't think too hard...

 

[mike93lx]

Flat leg under the wall, upright leg up the side?

Yes

Don't think too hard...

That's at least half the fun though.

If I had faith in the "7000 lb" set, I'd probably just grab 1 set, but failure of a caster would probably cause another to fail, then I delay everything to probably another weekend.

Thinking time is free, thankfully

 

[tjansson]

You can use flat head screws in thin material, but you'll need clearance behind it, i.e., countersink the tapped hole too. Door hinges are an example. Kinda neat because flat head crews actually lock the position of the bolted part in in the shear direction.

 

[cvairwerks]

Mike: For a .250" thick plate, use the 5/16ths. When your head height is too close to the material thickness, you end up knife edging the countersink. That weakens it greatly and makes it easier to have the fastener wallow out the hole when side loaded.

 

[no704]

All moves are on good concrete? Maybe look at transfer balls?

 

[mike93lx]

All moves are on good concrete? Maybe look at transfer balls?

Yes smooth, but I don't know if those would really be any better. I have the limitation of needing to either mount to the side or place on skates, and doing the angle eliminated the risk of a skate platform breaking

 

[no704]

I used them once for a pretty high load fixture that had height constraints. Worked pretty well, but they do not get along with dirt!

 

[PCustoms]

VEVOR 4pcs Machinery Mover, 8T Machinery Skate Dolly, 17637lbs Machinery Moving Skate, Machinery Mover Skate w/ 360° Rotation Cap and 4 Rollers, Heavy Duty Industrial Moving Equipment, Yellow https://www.amazon.com/dp/B0CKWZTJTL?tag=atomicindus08-20

 

[mike93lx]

VEVOR 4pcs Machinery Mover, 8T Machinery Skate Dolly, 17637lbs Machinery Moving Skate, Machinery Mover Skate w/ 360° Rotation Cap and 4 Rollers, Heavy Duty Industrial Moving Equipment, Yellow https://www.amazon.com/dp/B0CKWZTJTL?tag=atomicindus08-20

I need to rotate it 90 degrees in a pretty tight space, so I didn't think machinery skates would be the right choice.

 

[mike93lx]

I used them once for a pretty high load fixture that had height constraints. Worked pretty well, but they do not get along with dirt!

I dont have any height clearance issues. There's almost 6' above it.

 

[no704]

Put a trailer under it!

 

[mike93lx]

Put a trailer under it!

But then I'd need a real truck to pull it... Before you know it, I own a f450 Ford ranger and a gooseneck, and my shelter is still in the same place

 

[VR6ix]

Mike: For a .250" thick plate, use the 5/16ths. When your head height is too close to the material thickness, you end up knife edging the countersink. That weakens it greatly and makes it easier to have the fastener wallow out the hole when side loaded.

Just make the thru hole larger to leave a short straight flat section. The c.sink does all the work, the thru hole is just along for the ride. Pushing that secondary burr out the back side of the part can also be problematic during handling and installation.

We have a spreadsheet at work for metric and imperial and all the thickness we deal with and adjust customer parts accordingly. Many CAD programs pull standards that don't cut the c.sink deep enough to actually make the head flush or a few thou under flush. As noted above it's only an issue when the material is thin enough that the flathead fastener is now interfering with the base material and you need to c.sink both.

Occams Razor: just weld the dang casters on and zip-cut them off afterwards

 

[mike93lx]

Just make the thru hole larger to leave a short straight flat section. The c.sink does all the work, the thru hole is just along for the ride. Pushing that secondary burr out the back side of the part can also be problematic during handling and installation.

We have a spreadsheet at work for metric and imperial and all the thickness we deal with and adjust customer parts accordingly. Many CAD programs pull standards that don't cut the c.sink deep enough to actually make the head flush or a few thou under flush. As noted above it's only an issue when the material is thin enough that the flathead fastener is now interfering with the base material and you need to c.sink both.

Occams Razor: just weld the dang casters on and zip-cut them off afterwards

I'll admit it. I don't have a welder right now.

There, I said it.

 

[Wiz02]

I'll admit it. I don't have a welder right now.

There, I said it.

Oh the shame. P.S. I'm in the same boat.

 

[PCustoms]

I need to rotate it 90 degrees in a pretty tight space, so I didn't think machinery skates would be the right choice.

They're the perfect choice, you ever used a set?

 

[mike93lx]

They're the perfect choice, you ever used a set?

My many years of rigging aren't showing through?

 

[PCustoms]

My many years of rigging aren't showing through?

My bad.

As long as you get the ones that turn, you can spin equipment in place. Steer one skate at a time, get them head the right direction then (one level smooth ground) one guy should be able to push.

Moved whole assembly lines in a day using a few sets, even presses coveted in oil never slid off. 6k of wood would be easy.

I'd normally never suggest off brand soft something like this, but big picture these are so over rated there's little risk.

 

[mike93lx]

My bad.

As long as you get the ones that turn, you can spin equipment in place. Steer one skate at a time, get them head the right direction then (one level smooth ground) one guy should be able to push.

Moved whole assembly lines in a day using a few sets, even presses coveted in oil never slid off. 6k of wood would be easy.

I'd normally never suggest off brand soft something like this, but big picture these are so over rated there's little risk.

So they dont turn and you have to slide them to rotate, and the 360 degree table allows that to happen? Feels like the steel wheel ones would be easier to use. I had looked at these originally and felt like tuning would be a struggle.

Wonder if that's easier than dealing with casters that may not want to rotate and align to the direction of movement.

Its certainly a simpler solution to implement

 

[PCustoms]

So they dont turn and you have to slide them to rotate, and the 360 degree table allows that to happen?

Correct. They sell bars/handles that hook over the round cross brace. 4' handles let you twist the trolley in the direction you need. Lots of options and linkages, for a simple short move 4 skates are good.

Feels like the steel wheel ones would be easier to use. I had looked at these originally and felt like tuning would be a struggle.

Don't shoot me if I'm wrong, but I can't recall having issues with urethane wheels. Been almost 10 years since I've done a line move though.

Wonder if that's easier than dealing with casters that may not want to rotate and align to the direction of movement.

Its certainly a simpler solution to implement

Personally less then $100 to avoid a project so I can complete my project makes sense. By the time I bought wheels and made mounts I'd be in $200 and kill several weekends before I did any real work.

 

[mike93lx]

Correct. They sell bars/handles that hook over the round cross brace. 4' handles let you twist the trolley in the direction you need. Lots of options and linkages, for a simple short move 4 skates are good.



Don't shoot me if I'm wrong, but I can't recall having issues with urethane wheels. Been almost 10 years since I've done a line move though.



Personally less then $100 to avoid a project so I can complete my project makes sense. By the time I bought wheels and made mounts I'd be in $200 and kill several weekends before I did any real work.

Ok, you got me done.

 

[PCustoms]

Ok, you got me done.

I'm not responsible!

 

[no704]

Just go to the scrap yard and see what you can find in 1-2” pipe. A few chunks on each side and make like an egipfion.

 

[mike93lx]

Just go to the scrap yard and see what you can find in 1-2” pipe. A few chunks on each side and make like an egipfion.

I know pipe can work but it's not what I want to do for this.

 

[PCustoms]

egipfion.

I think I know what you were going for, but how the hell did you come up with THAT?

 

[rust in the eye]

What is your weight and dimensions?
Professional furniture dollies will take a tremendous amount of weight and they maneuver easily.
I have used them to hold stripped down car bodies and even balanced an entire shell on just one once.

 

[PCustoms]

What is your weight and dimansions?
GOOD quality furniture dollies will take a tremendous amount of weight and they maneuver easily.
I have used them to hold stripped down car bodies and even balanced an entire shell on just one once.

Post #4 says 6k lbs...

Dimensions are kind of irrelevant, but I thought of dollies too

 

[mike93lx]

What is your weight and dimensions?
Professional furniture dollies will take a tremendous amount of weight and they maneuver easily.
I have used them to hold stripped down car bodies and even balanced an entire shell on just one once.

6k lbs. Walls are about 6" thick, but only 4.5" is contacting the ground. 60" D x 103" W.

Since the weight would entirely be on the rails of a furniture dolly, I didn't want to risk collapsing one, nor deal with all the bulk