Depth Gage?

Kroll

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Guys I am drilling a 1/8 hole in the end of 3/4 rod but I also want it to be lets say at a dept of 1 1/16. So with this info I am in market for a dept gage so that I can drill a hole be it 1/8 or 1/2 dia to a measure depth.So looking on ebay I see there are more than a couple to chose from with all kinds of accuracy.While I am not looking for something that will split hair like .0001 but maybe .001 would be more like it.Shopping on ebay means used but price sure looks like some are new and some are used.So being a dept gage for me it won't be used all the time but just every once while.I am asking for suggestion on what to look for that I can measure the dept of maybe an 1/8 hole and larger to maybe depth max of 6"? You know the length of drill bit?Thanks guys the more I look on ebay my choices keeps changing,thought I would ask first before I hit the "Buy it Now" button.
 

mmcmdl

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So you're looking for a depth gage ? If I'm not mistaken , the rods in most are larger than 1/8" .
 

mmcmdl

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Easy to make a cheap depth gage also . If you need to be smaller than .125" , just drill a piece of material and slip some drill rod thru it . Put a screw in and its done . Measure the depth with a pair of verniers . ;) ( not that I like people not to spend their $$$$$ ) :big grin:
 

Uglydog

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If you plan to use it only occasionally, then you might consider making one.

Consider various lengths of drill rod (any metal rod would work). You could make some stops with set screws.

An even cheaper option is to use very fine thread machine screws of whatever diameter you need. Use two nuts. One to set the height the other as a jam nut.

Note: neither of these options have an integrated rule.

Other factors in a shop made gage is the base. A large base will help keep it straight when measuring. But it all comes down to what you need and how deep your pockets might be.

Should you buy one, either new or used, expect that you may need to use calibrate. Depending on tolerance you can use a 25' tape measure or ceramic gage blocks and everything in between.

Hobby Machining doesn't need to be expensive to do good work.

Daryl
MN



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WarrenP

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Calipers have a depth gauge built into them if you have one. not sure offhand if its over 1/8 of an inch wide though. I would check... could always make it an 1/8 wide.
 

Kroll

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Thanks mmcmdl and Daryl,Warren.I do have calipers but the end to use is bigger than 1/8 which I did check:(. mmcmdl I like the ideal of using 1/8 drill rod and Daryl like the ideal of making one also which I will have to research the choices. So off to check out some Youtubes and then out to garage to see about making myself one down dirty.
 

mmcmdl

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All you need is a piece of round stock about an inch long and some drill rod . Drill and tap yourself a locking screw hole , then you can measure that with your very nears ! :big grin: Or rectangal , square for the base .

I made up a few sets years back for setting up CNC lathes .
 

Jimsehr

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Buy the right tool and you will have it forever. Most rods are bigger then .125 dia.
But they do go that small. I have about 5 depth micrometers. One set has a blade
for checking in narrow places.
 

hman

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I'm pretty sure I've seen dial calipers that used a piece of wire (maybe .040" to .060") for a depth rod. It might have been a cheapo plastic caliper. These are graduated to 1/100 inch, not 1/1000. But you're drilling the holes, so the bottom has the same taper as the drill bit ... and without a flat bottom to measure to, trying to get 1/1000" accuracy is an kinda an exercise in futility.
 

RJSakowski

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One way to measure the depth oif a small hole is to insert a rod of known length and measure the stickout. Subtract that measurement from the rod length for the hole depth.

Another way if the thickness of the workpiece can be measured is to insert a measured rod slightly longer than the depth of the hole and measure the distance from the rod end to the far side of the work. The hole depth is equal to the rod length plus the work thickness minus the combined thickness. This method can be very accurate if a micrometer is used for the measurements.

Hole depth is customarily defined as the the depth of the hole at full diameter. When using a rod to measure hole depth, the rod diameter should be very close to the diameter of the hole for accurate measurement.
 

mikey

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Kroll, I use a home made depth gauge for small holes that works really well. It is just a 3" long piece of brass drilled to receive a 5" long piece of stainless fishing leader that is 0.075" OD (#26 fishing leader). The leader has a rounded end and the other end is flat. I drilled the hole in the 1/4" OD brass thing that you hold onto from both ends. Drills this small will not drill straight, which is good in this case because the through hole will be slightly mis-matched. This provides just enough tension on the wire to hold it firmly in place but it moves with just a little pressure.

To use it, you stick the wire in the hole and push the brass body of the holder down to meet the top of the part, then you pull it out and measure the wire with a rule or the tail of a dial caliper. This is not the most accurate way to do things but it is very fast and accurate enough for gauging hole depth.
 

Chewy

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As with RJ just make a rod the correct length and keep dropping it into the hole. Run your finger nail over it until it doesn't catch. If you want more precision than this make two rods, go and no go maybe .001 apart on either side of dimension and use a calibrated fingernail. :)

I like the homemade depth gauge from Epanzella and will make one. Beats using a rod and pair of Visegrips. Charles
 

Jimsehr

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As with RJ just make a rod the correct length and keep dropping it into the hole. Run your finger nail over it until it doesn't catch. If you want more precision than this make two rods, go and no go maybe .001 apart on either side of dimension and use a calibrated fingernail. :)

I like the homemade depth gauge from Epanzella and will make one. Beats using a rod and pair of Visegrips. Charles

I looked at eBay and see that you can buy a plastic caliper with a 1/8 depth stem for less then $10 bucks. I don’t think I could make a homemade tool for that little money.”
 

francist

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You can also get those tire tread gauges for pretty cheap. Supposedly they’re pretty accurate but they are limited to about an inch of depth, max.

-frank

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