Grinding Software Testing

Knives and blades tested:
Thin behind the edge double-bevel knives – two knives 0.5 mm and 1.2 mm behind the edge (thickness at the spine 2 mm and 3.7 mm);
Thick behind the edge double-bevel knives - two knives 1.6 mm and 2.5 mm behind the edge (thickness at the spine 4.5 mm and 6.5 mm);
Single-bevel knives – two knives 0.8 mm and 1.8 mm behind the edge (thickness at the spine 2.5mm and 3 mm).
2mm double-bevel steel plate - 2 mm behind the edge.
3mm double-bevel steel plate - 3 mm behind the edge.

Thickness behind the edge in knives is measured the following way:
when re-sharpening close to the original edge angle - at the edge bevel;
when re-profiling to a lower angle or sharpening a grossly dull knife - within 3-5 mm from the edge bevel.
Thickness behind the edge in the plate is constant and the same as the thickness of the plate.

The actual knives and blades used in the testing are shown below:

3mm double-bevel plate - 3 mm behind the edge

Grinding wheels used in the test:
Coarse #80, Medium #400 and Fine #1000. These particular grinding wheels differ in diameter by 4 mm, and our software is used to match the grinding angle.

Tormek machines used in the test:
We used in the testing two Tormek T-7, two Tormek T-8, and one Tormek T-4 machines, 5 total.

Laser protractor used in edge angle measurements:

CATRA Laser Knife Edge Protractor, accuracy ±0.2 degree.

Sharpness tester:
PT50B

Applet 1 - Grinding Angle Setter for Tormek

Angles are given in degrees per side.

MODE 1: Sharpen a knife

Target angle in the calculation	10°	12°	14°	16°	18°	20°
0.5mm behind the edge double-bevel knife – ground angle	10°	12°	14°	16°	18°	20°
1.2mm behind the edge double-bevel knife – ground angle		12°		16°		20°
1.6-2.5mm behind the edge double-bevel knives – ground angle	10°	12°	14°	16°	18°	20°

Target angle in the calculation	16°	18°	20°
Single-bevel knife – ground angle	16°	18°	20°

MODE 2: Grind a 3mm double-bevel plate blade

Target angle in the calculation	12°	14°	16°	18°	20°
3mm double-bevel plate– ground angle	12°	14°	16°	18°	20°

MODE 3: Re-profile a knife to a lower angle

Original edge angle	20°
Target angle in the calculation	12°
Thin double-bevel knife – ground angle	12°
Thick double-bevel knife – ground angle	12°

Original edge angle	20°
Target angle in the calculation	16°
Single-bevel knife – ground angle	16°

Applet 2 – Frontal Vertical Base for Tormek

Angles are given in degrees per side.

MODE 1: Re-sharpen at the original edge angle

Target angle in the calculation	10°	12°	14°	16°	18°	20°
0.5 mm behind the edge double-bevel knife – ground angle	10°	12°	14°	16°	18°	20°
1.2 mm behind the edge double-bevel knife – ground angle		12°		16°		20°
1.6-2.5mm behind the edge double-bevel knives – ground angle	10°	12°	14°	16°	18°	20°

Target angle in the calculation	16°	18°	20°
Single-bevel knife – ground angle	16°	18°	20°

MODE2: Tormek Leather Wheel honing
Our software is used to match the ground angle to the honing angle.

Check the ground and honing angle match by the marker method and sharpness tester

Actual edge angle	12°	16°	18°	20°
Thin double-bevel knife	match	match	match	match
Thick double-bevel knife	match	match	match	match
Single-bevel knife		match	match	match

The BESS Sharpness Tester PT50 showed 60-80 BES for the 12° and 16° edge honed with the Tormek honing paste at the ground angle, and 150 BESS for the 20° edge.
This is in line with the sharpness reading we’ve shown earlier for knife steels:
- a burrless 12 dps edge is scoring 50-70 BESS, while the residual burr will show over 100 BESS;
- a burrless 14-16 dps edge is scoring 70-90 BESS, while the residual burr will show over 120 BESS;
- a burrless 20 dps edge is scoring 80-150 BESS, while the residual burr will show over 150 BESS.

Deburr serrated knives

Sharpness under 100 BESS in the serrations.

Cross-check between the Grinding Angle Setter and Frontal Vertical Base

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Grind a 2mm double-bevel flat blade

Angles are given in degrees per side.

Target angle in the calculation	10°	11°	12°	13°	14°	15°	16°	17°	18°	19°	20°
Grinding Angle Setter – ground angle	10°		12°		14°		16°		18°		20°
Frontal Vertical Base – ground angle		11°		13°		15°		17°		19°

Applet 3 – Paper Wheel Angle Setter

Testing done on:
1 x Gritted paper wheel, diameter 260mm.
3 x Slotted honing paper wheels: diameter 256mm, 251mm and 247mm.
3 x 8” Buffers & Grinders running 10” paper wheels.

GRITTED PAPER WHEEL – GRINDING
Check the edge angle ground on a gritted paper wheel by the CATRA laser protractor.

TARGET edge angle	10°	12°	14°	16°	18°	20°
Thin double-bevel knife	OK	OK	OK	OK	OK	OK
Thick double-bevel knife	OK	OK	OK	OK	OK	OK
Single-bevel knife				OK	OK	OK

SLOTTED PAPER WHEEL – HONING
Check the match of the edge angle ground on Tormek or gritted paper wheel to the honing angle on slotted paper wheel by the marker method and sharpness tester.

ACTUAL edge angle	10°	12°	14°	16°	18°	20°
Thin double-bevel knife	match	match	match	match	match	match
Thick double-bevel knife	match	match	match	match	match	match
Single-bevel knife				match	match	match

BESS Sharpness tester shows 50-55 BESS for a 12 dps edge, 70 BESS for a 15 dps edge, and 130 BESS for 20 dps edge honed on paper wheels.
This is in line with the sharpness reading for knife steels we’ve explained above, and better than what we see in edges honed on Tormek leather wheel.