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I have a HF mini-mill with the usual 7/16 slots, and a matching clamp kit. The studs that came with the kit are supposedly 3/8-16, and they work with the supplied nuts. However, to mount my angle plate on the table I need shorter bolts, with heads. When I try standard 3/8 bolts from other sources, the threads don't match exactly. A bolt gets stuck after going half way through a nut. Has anyone else had this problem? Do I need to get bolts manufactured to a special standard? Thanks in advance for any comments.
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Are the standard bolts you are trying to use 16 pitches per inch? Sounds like you might have a mismatch there.
On Saturday, May 7, 2022, 03:00:11 PM PDT, azk7tv <ebasilier@...> wrote:
I have a HF mini-mill with the usual 7/16 slots, and a matching clamp kit. The studs that came with the kit are supposedly 3/8-16, and they work with the supplied nuts. However, to mount my angle plate on the table I need shorter bolts, with heads. When I try standard 3/8 bolts from other sources, the threads don't match exactly. A bolt gets stuck after going half way through a nut. Has anyone else had this problem? Do I need to get bolts manufactured to a special standard? Thanks in advance for any comments.
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Have you tried an m10 bolt? ? On Sat, May 7, 2022 at 6:11 PM Jonathan Mackenzie via <jonathanmackenzie= [email protected]> wrote:
Are the standard bolts you are trying to use 16 pitches per inch? Sounds like you might have a mismatch there.
On Saturday, May 7, 2022, 03:00:11 PM PDT, azk7tv < ebasilier@...> wrote:
I have a HF mini-mill with the usual 7/16 slots, and a matching clamp kit. The studs that came with the kit are supposedly 3/8-16, and they work with the supplied nuts. However, to mount my angle plate on the table I need shorter bolts, with heads. When I try standard 3/8 bolts from other sources, the threads don't match exactly. A bolt gets stuck after going half way through a nut. Has anyone else had this problem? Do I need to get bolts manufactured to a special standard? Thanks in advance for any comments.
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Yes, the common 16 per inch threads are incredibly close. The bolt goes in quite far before it gets stuck.
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I went to ACE hardware and tried M10 bolts with two different pitches. They were both too thick to even start going in.
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??? ??? take the nut to the hardware store & see what fit's
it . They do make/sell metric holdown kits
??? ??? animal
On 5/7/2022 2:31 PM, azk7tv wrote:
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Show quoted text
I have a HF mini-mill with the usual 7/16 slots, and a matching
clamp kit. The studs that came with the kit are supposedly 3/8-16,
and they work with the supplied nuts. However, to mount my angle
plate on the table I need shorter bolts, with heads. When I try
standard 3/8 bolts from other sources, the threads don't match
exactly. A bolt gets stuck after going half way through a nut. Has
anyone else had this problem? Do I need to get bolts manufactured
to a special standard? Thanks in advance for any comments.
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The M10 being too big would make sense.? 3/8 inch = 9.5 mm.
Put a scale and a dial caliper on your bolts and tell us what you get.? There are two thread pitches fairly easy to get on 3/8":? ?Coarse (UNC) 16 TPI and Fine (UNF) 24 TPI.
Easy to forget, but when you post a question, try to remember to tell all you've done right from the start (like the trip to Ace).
Hank ____________________________________
On Saturday, May 7, 2022, 06:33:31 PM EDT, azk7tv <ebasilier@...> wrote:
I went to ACE hardware and tried M10 bolts with two different pitches. They were both too thick to even start going in.
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I forgot to mention that I have many 3/8-16 bolts in my workshop, and they are an excellent match when pressed together side by side with the bolts from the kit. No way I should be looking for something like 24 tpi. Also, there is a bit of variation between different nut/bolt combinations within the kit. And, with the kit bolts as well as with my 3/8-16's, in most cases it seems much harder to put the bolt in from the bottom of the nut. Maybe the kit manufacturer intentionally made the female threads to seize before they get in far enough to touch the bottom of the slot (and prevent the nut from sliding in the slot)? Come to think of it, when I use a second nut on the top of a bolt, I would probably be thankful for the bolt seizing in the lower nut. If this is the explanation, there still seems to be a case of sloppy tolerances in manufacturing...
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If you are referring to the T-nuts, they are purposely crimped at the bottom so that a bolt will not continue threading through, which could force the T-nut to push up and fracture the top of the T-slots in your cast iron table. But the hex nuts should allow a bolt to pass through completely.
John
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T-nuts sometimes come with the threads upset on the bottom or not completely threaded through. This is to keep the user from threading all the way through the t-nut and then jacking the t-nut into the bottom of the table. I have seen pictures of tables with a chunk of the slot missing where this was taken to an extreme.
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I would make nuts to fit.
I use O1 or W1 tool steel for nut.
Dave?
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??? ??? I had totally forgotten about this & if you plan to
make your own? t-nuts? ( which is much cheaper then buying them if
you have the material ) keep in mind that you should peen the
bottom
??? ??? of the thread in the nut for table protection .
??? ??? animal
On 5/7/2022 5:06 PM, Steve Simpson
wrote:
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Show quoted text
T-nuts sometimes come with the threads upset on the bottom or not
completely threaded through. This is to keep the user from
threading all the way through the t-nut and then jacking the t-nut
into the bottom of the table. I have seen pictures of tables with
a chunk of the slot missing where this was taken to an extreme.
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Yes, I was referring to the T-nuts. Now it makes sense to prevent the bolts from going through all the way. In practice some of the bolts in the kit did go through anyway, which confused me. Anyway, I was trying to mount an adjustable angle table onto the mill table, using just standard 3/8" bolts with heads. That requires bolts of rather precise length, maybe assisted by a washer or two. In this situation it would be easier to find a useable bolt length if the bolt were able to go through the T-nut a bit. OTOH, I could have used a clamp + bolt as provided by the kit, but that would take up extra space. In this case I think I will cut some bolts to fit.
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??? ??? I also saw somewhere that some import 1-2-3 blocks have
different hole sizes , like their threaded for a 3/8 16 but you
cant put a 3/8 bolt through the non threaded holes . DId your hold
down
??? ??? kit come with any separate threaded stud's? There's
always all-thread to make some from .
??? ??? animal
On 5/7/2022 7:07 PM, azk7tv wrote:
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Show quoted text
Yes, I was referring to the T-nuts. Now it makes sense to prevent
the bolts from going through all the way. In practice some of the
bolts in the kit did go through anyway, which confused me. Anyway,
I was trying to mount an adjustable angle table onto the mill
table, using just standard 3/8" bolts with heads. That requires
bolts of rather precise length, maybe assisted by a washer or two.
In this situation it would be easier to find a useable bolt length
if the bolt were able to go through the T-nut a bit. OTOH, I could
have used a clamp + bolt as provided by the kit, but that would
take up extra space. In this case I think I will cut some bolts to
fit.
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I have referred to bolts/studs that came with my kit. Those came in different lengths, with male threads on both ends. When I tried a few in the T-nuts, some went all the way through, although then seizing at some point.?
My 1-2-3 blocks were a separate purchase and not part of the clamping kit. As you stated, they have two kinds of holes. Most of the holes are too small for a 3/8, but there are 5 holes threaded for 3/8-20. Those 5 holes are all on the biggest face of the block, located as a centered "5" face of a gambling die.
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I've done that for two different mill tables (different T-slot
sizes) and a rotary table (yet another size).
I just checked the clamp kit I bought with our new mill, it's bigger
than an M10.? Possibly because this is for a large mill.
I don't have any large imperial bolts to check it against.
On 5/8/22 04:39, davesmith1800 wrote:
I would make nuts to fit.
I use O1 or W1 tool steel for nut.
Dave?
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Goryachiy Klyuch, Russia
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They do for some reason, I use 8 mm to go through the unthreaded holes in the 123 blocks. I also had to run a 3/8 die over my bolts to make them fit. They are okay for the price and you cannot get Australian made. US made freight kills the deal unfortunately.
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Chris (CB)
davesmith1800
Jerry Durand