M-48 Tank Barrel Damascus Steel Billets (Pre-Cut)

• 40 × 6 mm ≈ 1.57 × 0.24 in (precise: 1.5748 × 0.23622 in)

Forging

• Forge at 1742–1976°F (950–1080°C).
• Cool slowly after deformation — do not quench from forging temperature.
• Soft annealing is required before further machining after any hot working.

Machining M-48 billets are delivered soft-annealed and are ready to machine. The weld layers will not separate during machining.

Soft Annealing (required after hot working only)

• Heat slowly to 1328°F (720°C) and hold for 2 hours.
• Reduce temperature to 1202°F (650°C) and hold for a further 2 hours.
• Cool slowly in the furnace.
• Remove once the billet temperature is below 570°F (300°C).

Hardening M-48 billets are composed of M-48 Patton tank cannon barrel steel combined with tool steel. The exact alloy composition is proprietary. The steel behaves as a high-alloy carbon Damascus and is heat-treated accordingly.

• Heat to 1562°F (850°C) and hold until fully soaked.
• Quench in oil.
• Deep freezing after hardening is optional but recommended for improved stability.

Tempering

• Temper immediately after hardening (or after deep freezing if performed).
• Temper in two separate cycles of at least 1 hour each, cooling to room temperature between cycles.
• 2 × 1 hour at 356°F (180°C) → approximately 62–63 HRC for knife blades.
• Increasing the tempering temperature reduces hardness and increases toughness — adjust to your intended application.
• Because the exact composition is proprietary, we recommend testing hardness on a scrap section before committing to a final tempering temperature.

Surface Preparation

• After hardening, sand to a consistent finish — 400 grit minimum, up to 1200 grit for a finer pre-etch surface. Work through each grit cleanly before moving to the next. Scratches from lower grits will be amplified by the etch.
• Do not buff after sanding — buffing closes the surface and reduces pattern contrast.
• Wash thoroughly and dry with a clean cloth.
• Degrease with acetone or denatured alcohol immediately before etching.

Etching

• Always wear protective gloves and goggles and work in a ventilated area when handling acids.
• Use ferric chloride (FeCl₃, 15–50% solution in distilled water) or sulfuric acid (H₂SO₄, 15–30%). Both produce strong results on high-alloy carbon Damascus. Gator Piss is also confirmed compatible.
• Do not use muriatic acid — it attacks both steel types equally and produces flat grey with no pattern contrast.
• Heat your chosen etchant to approximately 122°F (50°C) in a water bath for consistent, controlled results.
• Suspend the billet freely in the etchant — do not let it rest on the bottom of the container.
• Because the exact steel composition of the tank barrel Damascus is proprietary, approach etching methodically: use short passes and check contrast frequently rather than following a fixed time. The 320-layer structure is dense — the pattern will emerge quickly and does not require the same etch depth as lower-layer-count steels.
• Between each pass, remove the billet, neutralize in a baking-soda solution, and lightly brush with a soft toothbrush to remove smut and surface oxides before returning to the etchant.
• Do not buff after etching — buffing destroys the contrast you have developed.

Developing Contrast

• After your final pass, neutralize thoroughly in a baking soda solution and rinse completely.
• For greater contrast, lightly sand with fine sandpaper (2000 grit or finer) to polish the raised bright layer while leaving the recessed dark layer at depth. The high layer count rewards this step — the fine, dense pattern becomes exceptionally pronounced with light post-etch sanding.

Final Steps

• Rinse and dry completely.
• Apply a protective oil or wax to prevent oxidation. Tank barrel Damascus, like all carbon Damascus, will develop a patina over time — regular oiling after handling is recommended.