Coated M-HSS Twist Bit

Images taken in a controlled environment or with a posed subject. All subject types.

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J_Rogers
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Joined: Mon Aug 09, 2021 2:29 pm
Location: North Carolina, USA

Coated M-HSS Twist Bit

Post by J_Rogers »

This is a Spyder Mach Blue twist [drill] bit. Nothing fancy and otherwise easy to obtain, they do make some neat subjects to photograph. It would be interesting to see what the true metal composition is given the marketing. Spyder claims they have added more tungsten than conventional M2 high speed steel, and I see that they still denote their "proprietary" composition with an M, so it's somewhere in-between M2 and any of the entry T type steels. Also no mention of the process used to coat them. I suspect its some oxide powder that's then plasma coated (easiest in terms of production lines.)

-Nikon D3300 on Newport XMS50-S stage, 2.75x magnification
-Reverse Nikkor 55mm f/2.8 @ f4
-Two Speedlight's at 1/128 power
260 image stack
drill-bit-stack-web-export-1.jpg
100% center crop
drill bit stack web export 100 percent crop.jpg

rjlittlefield
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Re: Coated M-HSS Twist Bit

Post by rjlittlefield »

Lovely!

Is there anything functional about the color grading, or is that just the way it turns out? (I am reminded of old-fashioned tempering processes, where the color was an important indicator.)

--Rik

J_Rogers
Posts: 87
Joined: Mon Aug 09, 2021 2:29 pm
Location: North Carolina, USA

Re: Coated M-HSS Twist Bit

Post by J_Rogers »

Yes the colors, surprisingly, are indicative of the functionality. Though I think you could claim on such a cheap mass produced part its equally the marketing aspect. Traditionally the interference colors on steel, or rather any metal, are indeed from the tempering process. Ceteris paribus; An oxide layer is deposited on the surface at different thicknesses depending on many factors. i.e., heat cycles, carbon deposits, temperature, grain structure, and so forth, thus creating vivid colors. You can generally gauge how well its been tempered based off the color and the gradation between the spectrum of colors. But, the wild colors here & likely other high-performance parts launching into various industries is from a multi-element nano-coating. Different chemical combinations will give different colors as well as rates applied and the temperature/ method used.

OSG Tool has a fairly large catalog with some nice pictures in it if you wanted to just look at a few of the colors produced on their products. Or their is a brief presentation titled "Mechanical and tribological properties of nano-layered periodical coatings" that is free on various publishing sites showing how well they actually work.

rjlittlefield
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Re: Coated M-HSS Twist Bit

Post by rjlittlefield »

Thanks for all the info -- very interesting!

I found the presentation at https://www.researchgate.net/publicatio ... l_coatings .

Aside: Here's a new type of glitch! That page offers an option to "Read file" online. I tried the "Read file" first, and got really Really excited on page 3 because I've never seen a number like 1.9e-92 in an engineering presentation. But then I got suspicious, used the "Download file PDF" (which actually gave me a PowerPoint .pptx), and learned that the trailing "2" in "-92" was totally spurious, just some mistake in the rendering. The real value is just a boring old 1.9e-9 .
ReadFile_vs_Download.jpg
Anyway...

The multi-layering described in the presentation is new to me for this sort of application. I was expecting to see just one or two layers, but the presentation describes 12-36 layers, alternating cobalt and amorphous carbon, for a total thickness around 200 nm. The individual layers are way smaller than wavelength of light -- the presentation lists 1.5 nm to 16 nm. If the coatings described in the presentation are vividly colored, anything like the blue stuff shown in this thread, then I'm not quite sure how to think about the way the light interacts with the layers. For the light, a reasonable starting point might be to think of it as a single layer of some intermediate refractive index, variable colors then resulting from differences in the total coating thickness.

--Rik

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