Drilling 5/8 holes in stainless.

[Wotname]

Originally Posted by GILow

They are 118, I just checked. Bordo’s Quicksilver range. Nice drills for everything else I’ve used them on. But my set maxes out at 13 mm and they don’t even come close to the performance of the Sutton INOX series drill bit I have in half inch.

OK, thanks for checking. IMO, this is the marketing hype I referred to earlier. IME, a spilt point on 118 degree is not really much advantage except for perhaps preventing some possible bit wandering in the hands of a novice.

But if it sells more product, I guess it is good for Bordo!.

[GordMay]

At ±82 HRC* [give or take], Tungsten Carbide is much harder than cobalt, or HSS [68 -70 HRC], and will last longer, and run much faster [tho’ still slowly] than its less wear and heat-resistant cousins.
This brittleness, along with cost, is carbide’s major Achilles’ heel.
Where cobalt will flex somewhat, in the face of radial cutting forces, carbide will, in many cases, shatter. This means that proper alignment is critical for tool life, and hole accuracy [which is true of any drilling operation].

* HRC = Hardness Rockwell Scale Cone
Larger numbers correspond to harder materials.

[coopec43]

Originally Posted by GordMay

At ±82 HRC* [give or take], Tungsten Carbide is much harder than cobalt, or HSS [68 -70 HRC], and will last longer, and run much faster [tho’ still slowly] than its less wear and heat-resistant cousins.
This brittleness, along with cost, is carbide’s major Achilles’ heel.
Where cobalt will flex somewhat, in the face of radial cutting forces, carbide will, in many cases, shatter. This means that proper alignment is critical for tool life, and hole accuracy [which is true of any drilling operation].

* HRC = Hardness Rockwell Scale Cone
Larger numbers correspond to harder materials.

Masonry Drill Bits
https://www.totaltools.com.au › Accessories › Drill Bits
"Plus, our masonry drill bits are made from the strongest materials and feature a tungsten carbide tip for maximum cut-through power. Shop by Product Type".

Well I'm not surprised sharpened masonry drills cut through SS without a problem.

[skipperpete]

Originally Posted by coopec43

Masonry Drill Bits
https://www.totaltools.com.au › Accessories › Drill Bits
"Plus, our masonry drill bits are made from the strongest materials and feature a tungsten carbide tip for maximum cut-through power. Shop by Product Type".

Well I'm not surprised sharpened masonry drills cut through SS without a problem.

Yes, but only if they’re sharpened properly, if done correctly on a diamond disc you can drill through a file but as wisely pointed out upthread, brittleness can be a problem as can too much heat, the silver solder (cemented carbide insert) lets go and the inserts come adrift…. But bear in mind how cheap masonry drills are, just sharpen up another one.

[dlj]

Originally Posted by GordMay

HRC = Hardness Rockwell Scale Cone

Not to be a pain, but HRC means Hardness Rockwell "C" scale. There are 15 different scales used in Rockwell Hardness testing all designated by different letters. "C" scale and "B" scale are the two more commonly used scales you might run across. There are also 15 superficial scales designated by a number and letter with the number meaning the force used and the letter indicating the indenter used. For example 15N, meaning a 15 kgf load using a diamond indenter.

The "B" scale is used for softer metals such as copper alloys, soft steels etc...

dj

[coopec43]

Originally Posted by skipperpete

Yes, but only if they’re sharpened properly, if done correctly on a diamond disc you can drill through a file but as wisely pointed out upthread, brittleness can be a problem as can too much heat, the silver solder (cemented carbide insert) lets go and the inserts come adrift…. But bear in mind how cheap masonry drills are, just sharpen up another one.

Spot on!

As far as sharpening was concerned I didn't have to worry about that as my Brother-In-Law was a Heavy Diesel Fitter with Caterpillar and when they had to drill out a broken engine stud from a block they drilled them out with a sharpened masonry bit (of course the engine stud would have been hardened high tensile steel)

PS I am puzzled by people posting on this thread that you cannot drill SS with a HSS drill bit. Have they ever drilled SS before? (Maybe they don't know how to use Google?)

"High-Speed steel drill bits – This type of bits are specifically designed for drilling stainless steel. The best HSS drill bits to use for this application are those with a Titanium Nitride tip to help reduce friction and heat."

https://www.thyssenkrupp-materials.c...tainless-steel

[GordMay]

Originally Posted by dlj

Not to be a pain, but HRC means Hardness Rockwell "C" scale...
dj

Indeed.
A Rockwell hardness tester consists of a penetrator, typically a round steel Ball, or diamond Cone) that is pressed into the surface of the material being tested, and a measuring device, that measures the depth of the indentation.
I've little knowledge of metallurgy, and may be confusing the "C" nomenclature.

[dlj]

Originally Posted by GordMay

Indeed.
A Rockwell hardness tester consists of a penetrator, typically a round steel Ball, or diamond Cone) that is pressed into the surface of the material being tested, and a measuring device, that measures the depth of the indentation.
I've little knowledge of metallurgy, and may be confusing the "C" nomenclature.

No worries. I'm really not trying to be a pain in any way. Nor am I trying to "call you out".... I just like to clarify with the desire to inform, not criticize..

Hardness testing is actually quite complex. In addition to the general framework you've mentioned above, the load applied is also a major variable. I could go on ad nauseum...

I never know how much I should write here as this is a sailing forum so I try to keep things to a level that could be useful to this community...

dj

[coopec43]

Originally Posted by dlj

No worries. I'm really not trying to be a pain in any way. Nor am I trying to "call you out".... I just like to clarify with the desire to inform, not criticize..

Hardness testing is actually quite complex. In addition to the general framework you've mentioned above, the load applied is also a major variable. I could go on ad nauseum...

I never know how much I should write here as this is a sailing forum so I try to keep things to a level that could be useful to this community...

dj

You are doing well

Can you guess (or do you know) what the hardness of a ball bearing (or roller bearing) in a motor car would be? And a piece of mild steel?

[dlj]

Originally Posted by coopec43

You are doing well

Can you guess (or do you know) what the hardness of a ball bearing (or roller bearing) in a motor car would be? And a piece of mild steel?

Hahaha - your question is pretty vague.

For automotive ball bearings, typically those are manufactured from either SAE 51200 or AISI 440C. when used in bearings, the hardness would typically be about HRC 64 and HRC 60, respectively.

Your second part, is asking "a piece of mild steel".... Now this is much more vague as the term "mild steel", while a common term found, is not a term that has metallurgical significance. It is typically a term used for low alloy carbon steels, of which there are a lot of alloys. Complicating that, there are also different forms and manufacturing techniques.

So for me to give you an answer, I'll define some parameters. Cold-rolled low-carbon steel strip per ASTM A109 can have a hardness range from a maximum of HRB 55 for dead soft material through a minimum of either HRB 90, for specific strip thickness, or minimum of HRB 84 for a different range of strip thicknesses in the "hard" condition...

But clearly, you aren't asking this question to "advance the knowledge of sailors and this sailing forum" are you....

dj

[GordMay]

Originally Posted by dlj

Hahaha - your question is pretty vague.

For automotive ball bearings, typically those are manufactured from either SAE 51200 or AISI 440C. when used in bearings, the hardness would typically be about HRC 64 and HRC 60, respectively...

So for me to give you an answer, I'll define some parameters. Cold-rolled low-carbon steel strip per ASTM A109 can have a hardness range from a maximum of HRB 55 for dead soft material through a minimum of either HRB 90, for specific strip thickness, or minimum of HRB 84 for a different range of strip thicknesses in the "hard" condition...
dj

Indeed.

Ball bearing hardness can vary [depending upon metal, & heat treatment]] from about 25 HRC [300 series S/S], up to over 90 HRC [Aluminum Bronze, Monel 400, & Tungsten Carbide].
440 series Stainless Ball Bearings have a minimum 58 HRC [up to 65 HRC] hardness.
Heat Treated Chrome Alloy Tool Steel is about 60 HRC.

[more]

Originally Posted by coopec43

Tell me where I am going wrong.
I did an online search and came up with.
What's the problem?

https://www.totaltools.com.au/4038-s...8?gad_source=1


Total Tools Seaford

49 Seaford Road
Seaford Meadows, 5169, South Australia
Phone: 0881840100

o my good so expensive and not carbide.
i pay this 50€
but this is not for ss this is for mini late. and seacock on boat,bow thruster,aluminium,normal steel not but over 10 mm for SS 316 best use https://www.aliexpress.com/item/3281...90.32819030890

[Thomas1985]

Out of curiosity how did you stamp/ cut the plates?

Drilling the holes is the easy part.

Did you have the plates fabricated? If so, why didn’t/ don’t you have them put the holes in them for you?

[more]

Originally Posted by Thomas1985

Out of curiosity how did you stamp/ cut the plates?

Drilling the holes is the easy part.

Did you have the plates fabricated? If so, why didn’t/ don’t you have them put the holes in them for you?

cutting ss plate 2-4 cm thick is 10 time easy ws drilling holes 2-4 cm.

and toll is cheap. for diy
angle grinder and ss cuting disc 0,8-2mm
surf 125mm Cutting Disc Steel Inox Stainless Super Thin

you need some guide like aluminium flat profile 4x1 cm xx meter????

slovly up-down and have perfect flat cut.

i have diamond very old 30+ year disc no name producer but cut like butter, more expensive brand dont cut nice.

[Thomas1985]

https://www.youtube.com/watch?v=FMzIHl1HMXc