Home Depot 1/4" Lag Screw

Page 2 of 10  

GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:
-snip-

If memory serves my 84 Reliant had TTY. might have been that 86 Escort with the Mitsubishi engine-- but they are the newest cars I've had the heads off of.
Here's a bit about them- but no models mentioned; http://www.aa1car.com/library/torque_to_yield_tty_head_bolt_tips.htm
Jim
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Same here, and TS sells their hardware by the pound. It's always where I go first. I just bought a boatload of grade 2 & 5 carriage bolts, nuts, washers, etc. for around $8 ($1.99/lb). The grade 8 are a little more expensive if you need them, but not unreasonable.
I was at Lowes later for something else, so just did a quick double check to see how far off they were. Grade 1 bolts alone were nearly $15.
8 (1/2 x4) = $8.80 ($1.10 each). 4 (1/2 x6) = $6.00 ($1.50 each).
The irony is that I'm using a plan I found at Lowes.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Indeed, the mark of a good hardware store is where you CAN by stuff by the pound.
--
EA



>
>
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

BTW: Using a drill gauge for sizing! We use a card with various holes in it, originally designed we think for sizing knitting needles? But the holes are marked in metric on one side and on the other in 64ths, 32nds etc. Very useful.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

And what diameter would that be, since lags are tapered? And if there were such a diameter, you would mean "root diameter" or minor diameter -- right?
But that's ok.... I'm sure the concept of conventional vs climb cutting is going to take another few weeks to properly gel in your brain -- all this other stuff will come in due time. Heh, mebbe you can study with yer buddee RicodJour.

Altho ahm no 'spert on wood, I doubt that the pilot hole should be exactly a root diameter (if there were one) for wood. After all, yer not tapping the wood like metal. Mebbe there is a woodworker's equiv to Machinery's Handbook that has this spec -- heh, mebbe even Machinery's handbook has it!
I'm sure there has to be some compression of the wood fibre, for adequate strength, when drilling pilots. 1/8" actually sounds about right.
--
EA



Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Snip

I have never seen a tapered lag screw unless it was "very" short, and the diameter you are looking for is the "body" diameter as described by McFeeleys screw sizing chart.

Actually you do want the pilot hole the same size as the body diameter.

You only want the threads cutting into the wood, 1/8" is too small.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 16 Dec 2009 08:03:04 -0500, "Existential Angst"

The 27th Edition lists the root diameter of a 1/4" lag bolt as .173".
The next natural drill size is .187, or 3/16".
Regards,
Tom Watson http://home.comcast.net/~tjwatson1 /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I measured a 1/4", just one, and its root measured .186-.187 top to bottom. I don't imagine lags are a precision item, tho.
And one of the links someone posted gives the pilot as 3/16 in softwood, 7/32 in hard! It also mentioned grease or vegeteable oil as a lube, but cautioned against soap.
1/4 lags are fragile, tho. I'd use 5/16 on anything semi-substantial.
--
EA

>
> The next natural drill size is .187, or 3/16".
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 12/16/2009 01:13 PM, Tom Watson wrote:

For optimum strength in solid wood you actually want to drill the pilot hole smaller than the root diameter. Specifically between 0.7 and 0.9 times the root diameter, depending on the density of the wood in question--softwood gets a smaller hole.
Chris
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 16 Dec 2009 13:25:08 -0600, Chris Friesen

Where does that come from?
Regards,
Tom Watson http://home.comcast.net/~tjwatson1 /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Watson wrote:

Long lore, at least...
I don't have a direct URL; I'd expect you'd find the information in some of the US Forest Products Laboratory technical publications. It was something I was taught way back in one of first HS ag-ed classes is first I recall it personally, anyway...don't recall if it was taught as a specific ratio, only "tubafores get smaller, rr-ties get bigger" was the gist of it. :)
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I don't see the point. The pilot hole sizes quoted work for nails where compression determines strength but I don't see any benefit in having a pilot hole of less than the root diameter of a threaded fastener.
Regards,
Tom Watson http://home.comcast.net/~tjwatson1 /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Watson wrote:

The point is to have a larger pilot-hole in softer woods than hardwood to minimize the effort of installation but to ensure a full bite which can be marginal if use a full root diameter for pilot, particularly in softwoods that tend often to "crumble".
No claim made (at least by me) that there's any _precise_ ratio other than the aforementioned bigger/smaller based on the material.
I'd still wager there is some information at US FPL but I've not taken time to search for it.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Hmmm....
Seems like it would be the opposite, the softer wood requiring a smaller pilot hole for more compression in surrounding wood to "ensure" a solid bite in a wood that tends to "crumble".
nb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
notbob wrote:

Mea culpa...yes, that was inadvertent swap of the intent I didn't catch... :( sorry.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

It's in "Wood As An Engineering Material", Page 7-11. What they say is:
"For low-density softwoods, such as the cedars and white pines, 40% to 70% of the shank diameter; for Douglas-fir and Southern Pine, 60% to 75%; and for dense hardwoods, such as oaks, 65% to 85%. The smaller percentage in each range applies to lag screws of the smaller diameters and the larger percentage to lag screws of larger diameters."
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
J. Clarke wrote:

Excellent reference, J. Thank you for posting that, it is very much appreciated!
The lag bolt which snapped off had an average shank diameter of 0.182". Sixty percent of this value is 0.1092, while seventy five percent of this value is 0.1365, which puts a pilot bit of 1/8" right in the middle.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 17 Dec 2009 11:19:09 -0800, "Jon Danniken"

What do you mean by "shank diameter"?
Machinery's Handbook lists the "body" or "shoulder" diameter of a 1/4" lag bolt as between .237" and .260". This is the area that is not threaded.
The "root diameter" is listed as .173". This is the diameter of the remaining cylinder after the threads are formed.
(American National Standard Square Lag Screws - ANSI/ASME B18.2.1-1996)
Regards,
Tom Watson http://home.comcast.net/~tjwatson1 /
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Tom Watson wrote:

Thanks Tom, I should have said the root diameter.
Jon
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

BUT Jon,,,,,, While it is a kewl reference that agrees with what you were using as a pilot hole, how did that work out for you?
The information could be out dated for readily available fasteners today. If might be a new publication using old data.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.