Carbide insert Torx screw

[Gordon]

I have a couple of boring bars which take a CCMT-21.51 Insert. I do not remember where I got them. Possibly Banggod. As near as I can figure out they are held in by a flat head torx screw which is 3-56 x 1/4" long. These screws are extremely easy to drop on the floor or into the chip tray. I just spent 1/2 hour crawling around on the floor hunting down the last one. I have not been able to find these screws except at some high price like $5 each plus shipping and even then I am not sure if they are the correct ones. Any idea where I can find them?

 

[Jasonb]

Most of the stuff coming out of China will have a metric thread are you sure they are not M2.5 x 6mm long. Also CCMT have a steep CSK hole and the screw usually has the taper to fit that.

As with everything you get what you pay for a branded screw will not round over or snap as quickly as a cheapie though unfortunately the price won't stop you loosing one. Not worth me giving sources as you probably want something closer to home

 

[Gordon]

Most of the stuff coming out of China will have a metric thread are you sure they are not M2.5 x 6mm long. Also CCMT have a steep CSK hole and the screw usually has the taper to fit that.

As with everything you get what you pay for a branded screw will not round over or snap as quickly as a cheapie though unfortunately the price won't stop you loosing one. Not worth me giving sources as you probably want something closer to home

I think that it is actually 2.5 x 6. I have ordered some of that size of the China variety. They are cheap ($7.99/10 pcs) and if that is the correct size I can order some of the better ones. I was getting the 3-56 specifications from US sites. They may actually both work. #3 screw is .099" OD and 2.5mm is .098". I don't have either a 3-56 tap or a 2.5mm tap to actually check.

 

[Scott_M]

Hi Gordon
Been there done that!
Fortunately for me I live near a large city that has a lot of industry and has several tool and die supply stores. When that happens I take my insert tool with me to the store and we figure out what it needs and I buy several. Try and google " Machinist tools and supplies near ( insert closest large city )"
When I do that both of my favorite stores show up. My favorite store even delivers at no extra charge.
Not sure where you are but worth a try.

Scott

 

[Gordon]

I had not tried to cross reference but a 2.5 mm screw is .045 mm pitch and 56TPI = .045 mm pitch and #3 screw is .099 dia =2.514 mm. They are the same thing.

 

[ignator]

I got replacements from eBay, so far they have not rounded out the torx head.

 

[krypto]

In this CCMT/CCGT-21.51 boring bar the screw size is M2.5-.45.

For screws, I ordered a 10 pack of each needed size straight from China years ago. Since I have plenty of spares, I never lose them. One thing that helps is using these quality Wiha Torx drivers as they have a small disc at the end that holds onto the screw when you remove it from the holder. These two drivers handle all the inserts in the tooling that I use.

 

[stanstocker]

I would go to the local hardware store and check through their small metric screw assortments. The two hardware stores in our small town have been able to provide the majority of my weird hardware needs, they even have the very fine thread hardened gun screws. Not always in the head style you want, but a socket head cap screw and washer will work in place of a button head quite often. You probably won't find any open stock at the big box stores, everything is in bags or sealed up little boxes and blister packs.

I'm probably lucky, our community still has a lot of work and recreational boats, and there are all sorts of weird fittings on boats!

 

[Gordon]

Unfortunately our town does not have much in the way of industrial supply stores. I live in Grand Rapids MI and the industry is primarily woodworking and office furniture. In the past there were two large General Motors plants and many die shops. There is one industrial supply near me but their local stock is very limited. They have a good stock in the Detroit branch but everything has to be shipped and the customer pays shipping. Several years ago they used to run a daily shuttle between Detroit and Grand Rapids so I could order something in the afternoon and it would arrive before noon. If I am just going to pick it out of a catalog and pay shipping I am better off ordering from Amazon.