Metric or SAE tiny bolt in DirectTV Receiver Model D11 DTV PN D11-800 mfg 4/9/07

[Robin Goodfellow]

I have three steel (stainless?) back bolts I want to re-use elsewhere that are on the back of the DirectTV Satellite Receiver Model D11 in my spare parts box.

My damn eyes can't _see_ what the threads are with the thread gauge! And the bolts are really short (maybe 1/4 inch long at best). I can barely hold it but worse I can't see the threads with my eyes.

All I want to do is use the three bolts (by drilling and tapping a hole elsewhere). But I can't _see_ even if the bolts are metric or SAE.

I have a cheap metric & SAE thread gauge but the whole thing is small.

The short bolts are close to an SAE 4x40 but I tapped that and it's not right.

Do you know if these would be SAE or Metric to start with? And do you know how I can find the bolt size for the three bolts holding the back cover on.

There are plenty of self-tapping screws of similar size so I'm only asking about the 3 very small bolts holding the cover on.

[Ed Pawlowski]

The last electronics made in the US was an RCA TV in the 1980s. I'd say they are metric.

If you can measure the diameter, this chart will tell you the size

[Anonymous]

Check with your nearest hardware store for a "professional" screw thread gauge. They usually have one, for customer use, mounted on the wall at the end of the aisle for nuts and bolts.

My ACE has one. It's yellow and about a foot square.

[hubops]

• 1 Lee Valley has the screw thread sets .. behind the counter so they don't disappear. :-) John T.

[Robin Goodfellow]

Ed Pawlowski [e-mail] asked

Using a one-inch mic, the bolt diameter (including threads) is 0.1155 inch. The bolt length, including the flat-topped Phillips head is 0.2230 inch.

Converting 0.1155 inch to metric units at this rapid tables site

out at 0.1155 inch x 25.4 = 2.9337 mm but from that chart how does it tell me whether the threads are metric or SAE?

[hubops]

ps : beware ! going to Lee Valley just to check a screw thread might end-up costing you .. ;-) ... you've been warned. John T.

[Marilyn Manson]

Why the need to re-use the bolts?

I get it that you have them, and I like reuse stuff too, but for all the trouble you're going through to find out what size they are, you could buy a few that match whatever size taps you have (e.g. SAE 4 x40) and complete your project.

$5, 100 screws...lots of spares. ;-)

[Ed Pawlowski]

.118 is M3. Unless it was made in the US it will be metric.

[Ralph Mowery]

You almost had the best idea. Do not fool with any of the gauges, just go through the local hardware store's box of nuts and find one that fits.

[Robin Goodfellow]

Ed Pawlowski [e-mail] asked

I have to drill a hole with the right drill & tap it with the right tap. Does that chart say which drill bit to use and which tap to use?

I hate assuming but I guess I'm stuck with metric as the guess. But that still doesn't tell me the thread count nor the drill bit.

I think it might be a 0.5 thread count as the best match on the screw gauge (but it's really hard to tell). If I look at the bottom image you gave me

I think the M3 says on the photo that it uses a 0.5 tap with a 2.50mm drill bit. All my drill bits are in inches, so back to the conversion site I ended up with a 3/32 inch bit (2.5mm / 25.4 = 0.09842519685 inch).

I'll try that and let you know.

[Ralph Mowery]

As you already have the holes tapped, just spend 2 bucks and buy the screws to fit the holes.

[Marilyn Manson]

He'll have to buy more than the 3 that he needs and his miscellaneous nuts and bolts inventory will *grow*, not diminish.

Been there, done that. ;-)

[Robin Goodfellow]

Marilyn Manson [e-mail] asked

Thanks for all the help. I solved the conundrum the old fashioned way.

I drilled a few 1/16th & 3/32nd holes in a spare piece of steel and tapped each one differently until I ended up with a 3/32 inch bit and a 0.6 tap.

I also had to use the 0/0 sharp Phillips to get the old bolts out of the DirectTV Satellite Receiver Model D11 case (they're security bolts, so I had to break a seal which suddenly voided my spare parts bin "warranty" I guess.

By the way, isn't the whole reason for the "spare parts" bin so that I do not have to go to a hardware store to get something as common as a bolt?

Anyway, if I drove all the way to the hardware store, I'd just buy a known size to be done with it (but then why even bother keeping spare parts?).

I think I need to buy a set of those bolt gauges because that would have helped. Is the Amazon one mentioned the one most of you choose to use?

[trader_4]

I was going to tell you that HD or Lowes, maybe both, have a little display in the bolt area with bolts and nuts so you can test what you have and identify them.

[Wade Garrett]

Magnifying glass...

[Robin Goodfellow]

Wade Garrett [e-mail] asked

Three hands... :)

I did end up using the magnifying class but the thread gauges read 0.5 when in reality they were 0.6 so even with a vice & magnifying glass I was wrong.

What I need, really, is one of those screw gauges that I can screw it into. I don't want to have to go to the hardware store just to check thread sizes.

Which screw gauge do you use if not the one listed from Amazon?

[Marilyn Manson]

What you need, really, is one of those good eye doctors. ;-)

(I feel ya, bro!)

[gfretwell]

Buy an assortment of metric screws and nuts. Just keep them sorted. Then you can match them up and you might even have the one you need.

[Jim Joyce]

For very short bolts, those little displays at Lowes and HD can be misleading. I took in a short bolt that seemed to thread into the 1/4" nut just fine, only to find out later that it was actually M6x1.0. Close but no cigar.