# Help figuring out what carbide insert for a grizzly boring bar



## ridgeway (May 31, 2014)

I just picked up a small Grizzy carbide shank boring bar.  Its 5mm and has a min bore of .237" and can't figure out what insert I need for it.  I purchased 10 molded (CCMT) from eBay and they are way too large and won't fit.  How do I determine the size I need?  Not much info on the Grizzly site as to a size.  I believe they want you to buy from them.  They only come in packs of 10 and I don't need that many, plus they are expensive!

Here is the bar:
http://www.grizzly.com/products/Solid-Carbide-Mini-Boring-Bar-5mm-Shank-Right-hand/T10248




Here is the inserts I need, but no idea what size I need.  All I know, its small!
http://www.grizzly.com/products/Carbide-Inserts-CCGT-for-Steel-and-Cast-Iron-pk-of-10/T10246



At $118 plus tax, plus shipping is getting up there for something I only need 2-3 of.


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## tertiaryjim (May 31, 2014)

If you find the same boring bar listed on the Griz site it will tell what insert the bar takes.
Other option is to measure the inset where the insert goes ( if you don't have an actual insert ) and reference that size in the insert listings to get the right one.

Jim


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## kd4gij (May 31, 2014)

You need CCGT insert. http://www.carbidedepot.com/Dynamiclanding.aspx?CategoryID=594
This link decodes the #s on the bar. http://www.carbidedepot.com/formulas-bb-d.htm
this for inserts. http://www.carbidedepot.com/formulas-insert-d.htm


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## ridgeway (May 31, 2014)

Thanks for the info.  Athough its helpful, i can't seem to find an insert small enough through any of the online carbide vendors.  These inserts are tiny!  I found a set of grizzly on ebay for $78 shipped.  Way cheaper than grizzly, 118 plus tax plus 16 shipping for a total of $144.  1 insert would last me a long time for all i would be using the boring bar for!


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## DMS (Jun 1, 2014)

They are probably 0.25ID (inscribed diameter). Take the end of a quarter inch drill, and place the insert on top of it. If the circle just touches the edges of the insert, that is a 0.25 ID insert. MSC has a ton. 0.25 ID inserts are the smallest I have seen, though it does look like MSC carries smaller inserts, they are listed under "boring inserts". Principle is the same, use a drill index to figure out what the inscribed diameter is, then you should be able to find what you are looking for.


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## dave2176 (Jun 1, 2014)

I think your inscribed circle is 5/32". Will a 5/32 drill bit fill the insert area? Reason behind it is the minimum bore of .237, bar diameter of .197 doesn't give enough room for a 3/16" inscribed circle to my thinking. Also the "03" in the bar number and the insert number from Grizzly points to 5/32".

Dave


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## Rangerjoe2 (Jun 1, 2014)

I had the same issue with bars I bought from them.  I sent them an email and they provided me with the information I needed.


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## ridgeway (Jun 1, 2014)

Dave, it is indeed a 5/32".  

I went and ordered the Grizzly 10 pack from eBay for $78.  Wasn't a bad price for all 10...


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## ridgeway (Jun 4, 2014)

I got the inserts from eBay for $78 shipped.  Extremely good deal considering Carbide Depot has them for $11.37 and only will sell packs of 10.  

http://www.carbidedepot.com/detail.aspx?ID=298890

http://www.mitsubishicarbide.net/mmus/enus/turning_inserts/no_srs/20086439

They are very tiny and I might need all 10 incase I drop one on a swarf covered floor!  

Anyhow, I am good to go...


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## xalky (Jun 4, 2014)

Those are indeed very tiny. I have what I thought were very small ones for a 3/8" boring bar, but those inserts are almost twice as big as yours, measuring .252".


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