Tabbed machine screws for Miter hardware

[Patty Hann]

I bought some hardware kits Powertec Miter Slot kits and wanted to get some extra screws.
They are "specialized" 5/16"-18 in that they have 2 tabs on either side of the head to lock them in place on the short miter bar.

I emailed Powertec and asked if the screws are available separately. No, of course they aren't, natch.
Rockler carries almost the same kit except the screws are 1/2" shorter, yet I doubt if I could have bought them separately there either.
And I want the longer ones anyway.

So does anyone know where I can get these screws? Thanks


Tabbed machine screw.jpg

[Edward Weber]

Bottom of page
https://www.ptreeusa.com/shop_safety_featherboards.htm
https://www.rockler.com/shop?w=miter+slot+hardware

Miter slot hardware

[Patty Hann]

Bottom of page
https://www.ptreeusa.com/shop_safety_featherboards.htm
https://www.rockler.com/shop?w=miter+slot+hardware

Miter slot hardware

So unless I missed something in your answer you are telling me to buy the kit I've already bought (bought 2 actually) just to get the screws?
Because if you read my question you'll see that I've already bought the kit and I want to get extra screws.

I'm asking (and I think it was pretty clear) "Does anyone know where I can get these screws?"
Thanks

[Edward Weber]

I didn't read your post correctly, sorry.
I don't know of anywhere else to get the screws only. An inexpensive kit is the next best option.

[Maurice Mcmurry]

You could put on an Optivisor, get out your Dermel and make your own out of a carriage bolt.

[Patty Hann]

You could put on an Optivisor, get out your Dermel and make your own out of a carriage bolt.

Yes, I could do that, I guess.
I've made much more elaborate stuff with a dremel (however, I actually use a Foredom, not a dremel ).
But someone makes these screws for Powertec and Rockler and anyone else (WoodRiver?) who sells these kits under their their own retail name.
Obviously there is tooling to make them for the kits.
(Then again, maybe the "tooling" is just an underpaid peon in foreign sweat shop with a Chinese dremel grinding down carriage bolts.)
I just can't see why they aren't available separately like so much other miter slot parts are.

[Maurice Mcmurry]

Thats an esoteric fastener it is a "flat countersunk nib bolt" metric is all I have found so far...

Flat Countersunk Bolts | Plow Bolts

[Maurice Mcmurry]

I sure do not find them in 5/16. M8 might work for the bolt. Having to replace the knobs would be frustrating.

The 5/16 bolt that is inside of a 3/8 sleeve anchor would require less carving for DIY than a carriage bolt.

Screen Shot 2022-09-25 at 7.10.11 AM.png
The heads are probably too small. They could mushroomed.

Photo on 9-25-22 at 7.47 AM.jpg

[Dan Hunkele]

The anchor bolt Maurice shows could have a 1/8" hole drilled and then drive a 1/8" roll pin through it for the stops.

[Wes Grass]

I downloaded a cad model of the anchor bolt from McM. It looks like the head angle is too shallow, 30° included.

From the picture it's about 60°. Otherwise, a slotted flat head with a scrap of something soldered or epoxied in the slot might work.

Easier to start with a standard hex head and turn it down. And drill the hole for the pin while you've got a flat surface to start on. Cheaper, available in various lengths ...

[Edward Weber]

I just can't see why they aren't available separately like so much other miter slot parts are.

I can understand your frustration, but one of the reasons you don't see them separately is that there is no other common applications for this style head.
It's designed to be used in conjunction with another piece and a nut to provide the pressure to tighten, these are only used as a set or as part of a tightening mechanism.
A wedged head bolt is unique in its application. If there were more hardware options or devices that could utilize this style head, they would be more available.

[Wes Grass]

Another question is why do you want just the screws. To make your own t-slot fixtures and not using the expanding aluminum inserts?

Other screws could work, either by chopping a hex pocket for the head, or just epoxy them in.

[Maurice Mcmurry]

What about using a hack saw to cut the slot in a slotted flat head bolt deep and inserting a little sheet metal nib with JB weld or brazing. I would try it but I used my last flat head 5/16 to fix the dump cart this morning.

[Patty Hann]

Another question is why do you want just the screws. To make your own t-slot fixtures and not using the expanding aluminum inserts?...

(How to answer this....) I've never been comfortable with having "only what is required" for a tool or appliance or whatever, especially if it is something that is easily(or quickly) misplaced/lost/broken/worn out.

I worked as an aerospace tech for 35 years, with lot of time spent on the manufacturing floor.
I had to repair a fair amount of rather expensive and hi-tech equipment, so I knew (in general) where electro-mechanical equipment was likely to fail first.
I also learned that operators can be careless with "Accessories'' .

Me (looking thru the Accessories kit): Where is the thingumabob?... I need it to adjust the sparkenzymaker.
Operator: I dunno, we never use it.
After spending 30-45 minutes hunting around for it, rummaging through drawers and cabinets and tool lockers (and doing it too many times for different equipment) I finally learned that I had to put together my own accessory kits.
(Note the plural...)

I have two of the miter slot kits... that's 4 shorty expandable miter bars , 4 knobs --which I have a ton of, along with washers -- and 4 nibhead bolts.
Just not comfortable with having only those 4 bolts.
And ...AND ... you can find stuff like this at garage sales, but it is typically missing something like (yep, that's right) screws, nuts, bolts.
I guess it's in my DNA ... my Dad was the same way (EE .. aerospace)

[glenn bradley]

In the realm of shop made I have used a 5/16-18 flat head, slotted head screw. I epoxy a bit of steel wire in the slot to grab the receivers intended for the tabs. These are not under a terrible amount of stress. They are just "keepers".