So these are just small pieces of metal marked NA51

bcstractor

Titanium

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Apr 25, 2004

Location

Monument CO USA

• Jul 3, 2011

• #1

They look like carbide blanks that are unground but NA51 would appear to mean "Nickel Alloy".

They were in a box of carbide bits from an auction. Before I throw them out I'd like to figure what they might be because, in a few decades, I haven't seen anything like it.

I know, very boring, rectangular .113 x .270 x 1.52.

Chris P

 

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Z

ZAGNUT

Hot Rolled

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Nov 30, 2008

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Israel

• Jul 3, 2011

• #2

what do they weigh?

 

9100

Diamond

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Nov 1, 2004

Location

Webster Groves, MO

• Jul 3, 2011

• #3

Right, weigh them and calculate their weight per cubic inch or whichever expression of density you prefer. Tungsten carbide is heavier than most metals. There is a nickel iron alloy 52 used for electrical leads sealed into soft glass, but it isn't nearly as heavy. There should be a table available online.

Bill

 

D

doug8cat

Titanium

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Philadelphia

• Jul 3, 2011

• #4

Just a really wild guess here and highly dependent on the material. If the composition of the material lends itself they maybe blanks for motot brushes, however from what I have gleaned so far probably much too hard fotr tha application.

 

bcstractor

Titanium

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Apr 25, 2004

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Monument CO USA

• Jul 4, 2011

• #5

12.3 g/cc - which is what makes them peculiar.

Chris P

 

morsetaper2

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Jul 2, 2002

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Gaithersburg, MD USA

• Jul 4, 2011

• #6

bcstractor said:

12.3 g/cc - which is what makes them peculiar.

Chris P

Click to expand...

12.3 g/cc is about .44 lb/cu inch for comparison.

Off the top of my head I know these approx general densities for comparison (lb/cu inch):

SS: .29
Copper: .33
Tungsten Carbide: .57

 

Yankee Metallic

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Elk City, Idaho USA

• Jul 4, 2011

• #7

I'm thinking TANTUNG or TANTALLOY.
Problem is that every manufacturer has their own recipe of chromium, tungsten, columbium, carbon, cobalt so it would be difficult to narrow it down by weight per volume.
You didn't mention how hard these mystery blocks appear to be.
TANTUNG is ususally in the low 60 Rc.

 

Yankee Metallic

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Elk City, Idaho USA

• Jul 4, 2011

• #8

OK it's not TANTUNG according to my math.
I weighed a piece of VR Wesson Tantung measuring 6.008 x .4985 x.2525"
it weighed 3.8275 oz. with a volume of .75623447 cc / in.
My math (math is not my friend) indicates 4.7605 oz per cu / in , .2975 lb per cu / in.
Eh?

 

U

USMCPOP

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Midlothian, Virginia

• Jul 4, 2011

• #9

I did see somewhere where Inconel 718 is called NA51 in the UK, but the density 8.19 g/cm3.

 

bcstractor

Titanium

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Apr 25, 2004

Location

Monument CO USA

• Jul 4, 2011

• #10

Ok - as to hardness. Regular file will not touch it. Diamond file will polish the surface.

I found a site that gave densities for the various grades of carbide and C5 can be at this low of a density. So may well be just blanks - but they are not going to be thrown away.

Chris P

 

4GSR

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Victoria, Texas, USA

• Jul 4, 2011

• #11

I got it's mating part NA52!

 

gbent

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Mar 14, 2005

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Kansas

• Jul 4, 2011

• #12

Put one in a vise and break it. Does it break easily? Sharpen one to use as a lathe bit. How does it grind and what color are the sparks? Use it as a tool bit. No need for a big cut, just want to see how long the edge holds up in the cut at 100 sfm, 250 sfm, or 500 sfm.

How magnetic are they?

 

Yankee Metallic

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Elk City, Idaho USA

• Jul 4, 2011

• #13

Solved

If you want to know if it is carbide, just test if it will scribe glass.
TANTUNG is hard as mid 60's but it won't scribe glass.

I agree with you that these are unground carbide blanks.
I did some carbide grinding for a customer at the first of the year. The blanks I ordered were approx. .020 oversize to allow for .010" grinding on each side.
Your given dimensions appear to support this.
.113 minus approx .020 = .0938 = 3/32"
.270 minus .020 = .250 = 1/4"
With the length obviously being 1 1/2"
The industry standard # is STB-38B per 2011 MSC
http://www1.mscdirect.com/CGI/NNSRIT2?PMPXNO=000000017694861
Worth about $3. apiece if they are C2 grade imported.

 

Last edited: Jul 4, 2011