Degussit Ruby Stones, Medium

$54.95 - $175.00
Total ---
Gesswein Ruby Stones and Files are made by Friatec-Degussit from pure, sintered crystals of synthetic ruby. No bonding material is used, so these stones are extremely hard and resistant to changes in shape. This is particularly important for quality precision grinding and finishing.

In addition, since Gesswein Ruby Stones have an outstanding resistance to wear, they are more economical to use than other comparable tools.

Use dry or with Gesswein Stoning Oil to grind, touch up or debur steel and carbide parts. Ruby stones are also recommended for use on materials such as glass, quartz and porcelain.

All are 100mm (4") long, medium grit in a variety of shapes & sizes.


Shape Inch Dimensions mm Dimensions*
A. Triangular 4" x 3/16" 100 x 4mm


4" x 1/4" 100 x 6mm


4" x 5/16" 100 x 8mm


4" x 3/8" 100 x 10mm
B. Square 4" x 3/16" 100 x 4mm


4" x 1/4" 100 x 6mm


4" x 5/16" 100 x 8mm


4" x 3/8" 100 x 10mm


4-3/4" x 1/2" 120 x 13mm
C. Round Pointed Available in Fine only. Refer to Fine page.
D. Round 4" x 3/16" 100 x 4mm


4" x 1/4" 100 x 6mm


4" x 5/16" 100 x 8mm


4" x 3/8" 100 x 10mm
E. Flat 4" x 1/4" x 1/8" 100 x 6 x 3 mm


4" x 5/16" x 1/4" 100 x 8 x 6 mm
F. Half Round 4" x 3/8" 100 x 10mm
G. Rhomboid Available in Coarse only. Refer to Coarse page.
H. Round, Tapered Available in Coarse & Fine only. Refer to Coarse page or Fine page.
I. Knife 4" x 5/8" x 1/8" 100 x 15 x 3>0.5mm
J. Tapered with
Round Edge
4" x 13/16" 100 x 30 x 7>2mm
*All dimensions have tolerance of ±0.1mm.

Ruby Stones are the ideal choice for deburring, blending, dressing, and fine polishing of molds & dies made of hard metals such as hardened tool steel, carbide and surgical stainless steel. Jewelers use them for sharpening of carbide and high speed steel engravers and other tools.

Mold & Die Uses:
  • Deburring ejector pin holes.
  • General deburring and edge breaking on mold steel and carbide.
  • Blending a surface where a straight edge meets a radius.
  • Polishing highly detailed areas on dies (after dressing Ruby Stone to a fine point).
  • Ruby Midget Files (see "Related Products" below) can be used in an Ultrasonic Handpiece for fast deburring and blending in ribs and other hard to reach areas. Ruby Stones cut faster than our very popular Super Ceramic Stones.
Medical Instruments:
  • Fine polishing of surgical stainless steel instruments.
Jewelers and Engravers:
  • Polishing and shaping of carbide & high speed steel gravers.
Find these items on these pages in our catalog:
  • 028
    These fine grinding stones are made of Degussit DD57 (sintered ruby) which is a homogenous mixed-crystal material. The main element is aluminum oxide. The characteristic red colour is the result of an admixture of chromium oxide.

    Because Degussit DD57 is a homogenous ceramic material which is bondfree, these stones cannot be classified in terms of "grit" but only in terms of the average grain size. The average grain size of types "fine" and "medium" is about 10µ. Type "coarse" has two average grain sizes at about 10µ and 100µ.

    No bonding material is used, so these stones and files are extremely hard and resistant to changes in shape. This is particularly important for quality precision grinding and finishing.

    In addition, since Degussit Ruby Stones and Files feature outstanding resistance to wear, they are more economical to use than other comparable tools.

    Use dry or with Gesswein Stoning Oil to grind, touch up or debur steel and carbide parts. Also recommended for use on materials such as glass, quartz and porcelain.