Sunken Bolt Alternatives
Sunken Bolt Alternatives
(OP)
Hi all,
I'm designing a product that is build out of CREUSABRO 4800: Hardness HB 370, Elasticity Modulus 205 GPa, UTS 1200 Mpa, YS 900 Mpa.
On some of the parts i want some of the heads of the bolts to be sunken below the surface, like a sunken bolt, but without actually using one as the manufacturing of the countersink is quite expensive and i want to keep the costs to a minimum
Was wondering what other solutions are there for using regular Hex Bolts or Cap-Head Bolts so that their head will be sunken bellow the surface (inserts or specialized bolts), so all i'll have to do is to drill a straight hole.
Thanks.
I'm designing a product that is build out of CREUSABRO 4800: Hardness HB 370, Elasticity Modulus 205 GPa, UTS 1200 Mpa, YS 900 Mpa.
On some of the parts i want some of the heads of the bolts to be sunken below the surface, like a sunken bolt, but without actually using one as the manufacturing of the countersink is quite expensive and i want to keep the costs to a minimum
Was wondering what other solutions are there for using regular Hex Bolts or Cap-Head Bolts so that their head will be sunken bellow the surface (inserts or specialized bolts), so all i'll have to do is to drill a straight hole.
Thanks.





RE: Sunken Bolt Alternatives
Also, you don't have to use two different drilling operations to make a hole, whether counterbored or countersunk. You can get a drill made that will do it all in one operation. Think of it like a center drill but with the drilling length suitable to whatever you're drilling, and the taper at 82 or 90 degrees to suit the hardware.
This keeps it to a single operation.
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
Thread the hole and use a stud?
Weld a stud on?
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
I'd be curious what else might pop up from others, though.
Personally, I'd accept the countersink/counterboring of holes because it's simple necessary for fastening. Common alternatives can be even more expensive.
RE: Sunken Bolt Alternatives
Basically the product is for the military, should protect electronics from shrapnel and explosion blast so the material is 8mm thick, that means i have enough surface area for some kind of insert that will act as a nut for the bolt.
I have two moving surfaces that are in a very close proximity to each other, if i use a bolt and a nut on one of those surfaces either the head of the bolt or the nut will interfere with the movement of the other surface, so im looking for a possible solution on how to eliminate this problem by hiding the bolt head (sunken bolt) or the nut (insert of some kind).
I've worked previously with brass inserts with knurled surface but for polymer applications, and not sure what type of inserts to use when it comes to steel alloys.
In the worst case scenario i'll go for the countersunk bolts, but this is a chance to find another elegant/simple solution for this problem.
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
Penn Engineering 'Pem Nuts' and the like may be a solution depending on various factors including material hardness, hole tolerances...
http://www.pemnet.com/fastening-products/pem-self-...
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Sunken Bolt Alternatives
RE: Sunken Bolt Alternatives
Military use means no through-hole fasteners, which is probably the reason for the question. A projectile hitting a through fastener will turn the rest of the fastener into shrapnel on the other side of the armor.
Seems like a design change is required to eliminate the need.
RE: Sunken Bolt Alternatives
Furthermore, all of the faces facing directly at the impact are without any openings.
But maybe you are right and there are no apparent less costly solutions, and a design change is the way to solve it.
Non the less, I've learned something new from KENAT.
Thank you guys for your help, but if anyone has more idias i will appreciate it.
RE: Sunken Bolt Alternatives
B.E.
You are judged not by what you know, but by what you can do.
RE: Sunken Bolt Alternatives
http://www.invert-a-bolt.com/1-2-fastener.php
RE: Sunken Bolt Alternatives