Ultra-thin precision steel strip for printing doctor blades and metering scrapers. C100S, SK95, 95Cr1, 420J2 — polished, slit to width, ready to mount.
A doctor blade — also called a printing scraper, metering blade, or Rakelklinge (German) — is an ultra-thin precision steel strip that controls ink or coating film thickness in printing and coating machines.
In flexographic and gravure printing, the doctor blade rides against a rotating anilox roller or engraved cylinder, wiping excess ink from the surface and leaving a precisely metered ink film in the cells. The blade tip must maintain a consistent contact angle and pressure across the entire print width — any variation causes banding, streaking, or uneven ink transfer.
In paper and board coating, doctor blades (also called coating blades or trailing blades) control the thickness of coating layers applied to the paper web. The blade scrapes excess coating from the paper surface, leaving a uniform film of controlled thickness.
The steel must be ultra-thin (typically 0.15–0.30mm), precisely flat, and have a polished, burr-free edge. Even microscopic surface defects translate directly into print defects visible on the final product.
Doctor blade steel is specified using Vickers hardness (HV), not Rockwell (HRC), as is standard practice in the printing industry due to the thin cross-section of the material.
| Thickness (mm) | Typical Width (mm) | Application | Notes |
|---|---|---|---|
| 0.15 | 30–60 | Standard flexo & gravure | Most common; fine ink metering |
| 0.20 | 40–80 | Heavy ink flexo, wide-web gravure | Higher stiffness for wider blades |
| 0.25 | 50–100 | Paper coating, board coating | Good rigidity for coating applications |
| 0.30 | 60–120 | Heavy coating, industrial scraping | Maximum stiffness; thick coatings |
Custom widths available via precision slitting. We stock master coils in 176mm width for on-demand slitting to your specification.
We offer four grades covering all doctor blade applications — from standard carbon steel to corrosion-resistant stainless. Each grade includes full chemical composition data per international standards.
DIN 1.1274 · EN 10132-4 · Carbon: 0.95–1.05%
The global standard for doctor blade steel. C100S delivers the optimal combination of hardness (HV 580–620), edge retention, and consistent wear behavior. Its high carbon content (~1.0%) produces a fine, uniform carbide structure after heat treatment, which ensures smooth, predictable blade wear without micro-chipping. This is the grade specified by major blade converters (Daetwyler, TKM, Allison Systems) as their default recommendation.
| C % | Si % | Mn % | Cr % | Ni % | Mo % |
|---|---|---|---|---|---|
| 0.95–1.05 | 0.15–0.35 | 0.30–0.60 | — | — | — |
JIS G 4401 · Equivalent to C100S · Carbon: ~0.95%
SK95 is the Japanese JIS designation for steel with composition equivalent to C100S. Popular in Asian markets (Japan, Korea, Southeast Asia) where JIS standards are the default reference. Performance characteristics are identical to C100S. If your existing supplier quotes "SK95" or "SK4", this is the matching grade.
| C % | Si % | Mn % | P % (max) | S % (max) |
|---|---|---|---|---|
| 0.90–1.00 | 0.10–0.35 | 0.30–0.50 | 0.030 | 0.030 |
Chrome-added variant · Carbon: 0.90–1.00% · Cr: 0.35–0.60%
95Cr1 adds chromium (0.35–0.60%) to the high-carbon base, improving wear resistance and providing moderate corrosion delay compared to plain carbon grades. The chromium refines carbide distribution for more uniform wear. Recommended for gravure printing with aggressive solvent-based inks, or applications where slightly longer blade life justifies the modest cost premium over C100S.
| C % | Si % | Mn % | Cr % | P % (max) | S % (max) |
|---|---|---|---|---|---|
| 0.90–1.00 | 0.15–0.35 | 0.30–0.50 | 0.35–0.60 | 0.030 | 0.030 |
DIN 1.4028 · JIS G 4303 · Cr: 12.0–14.0%
420J2 is a martensitic stainless steel with 12–14% chromium, providing true corrosion resistance. Essential for water-based ink systems, paper coating with aqueous dispersions, and food-packaging printing where rust contamination is unacceptable. Slightly lower hardness than carbon grades but eliminates corrosion-related blade changes. Also used for doctor blades in pharmaceutical and hygiene product packaging lines.
| C % | Si % | Mn % | Cr % | Ni % | Mo % |
|---|---|---|---|---|---|
| 0.26–0.40 | ≤1.00 | ≤1.00 | 12.0–14.0 | — | — |
| Property | C100S | SK95 | 95Cr1 | 420J2 |
|---|---|---|---|---|
| Carbon Content | 0.95–1.05% | 0.90–1.00% | 0.90–1.00% | 0.26–0.40% |
| Hardness (HV) | 580–620 | 580–620 | 590–630 | 500–560 |
| Corrosion Resistance | None | None | Low (Cr-enhanced) | Excellent |
| Wear Resistance | Excellent | Excellent | Very Good | Good |
| Edge Consistency | Excellent | Excellent | Excellent | Good |
| Ink Compatibility | Solvent & UV | Solvent & UV | Solvent, UV, mild aqueous | All (incl. water-based) |
| Cost Level | Standard | Standard | Standard+ | Premium |
| Best For | General flexo/gravure | Asian market standard | Gravure with solvents | Water-based ink / food |
Doctor blade performance is governed by four measurable parameters. We control all four in-house to ensure your blades perform consistently from the first meter to the last.
The blade tip radius determines initial ink metering behavior. A well-controlled radius (typically 10–25 μm) ensures rapid blade "break-in" and consistent print quality from the start of the run.
Our spec: Edge radius controlled within ±3 μm of target. Rounded or beveled edge profiles available. Burr-free guaranteed under 40x magnification.
Surface roughness directly affects ink adhesion to the blade face and cleaning ease. A polished surface (low Ra) reduces ink buildup and extends time between blade changes.
Our spec: Ra ≤ 0.2 μm on the blade surface. White polished finish as standard. Mirror finish available on request for premium applications.
Straightness deviation causes uneven blade contact pressure across the print width, leading to banding or streaking. This is especially critical on wide-web presses (1,000mm+ print width).
Our spec: Maximum deviation 1mm per 3 meters of blade length. Measured on a precision surface table with dial indicator at 100mm intervals.
Thickness variation along the blade length changes the bending stiffness, altering the contact angle and pressure at different points. This creates visible print density variation across the web.
Our spec: ±0.005mm thickness tolerance across the full coil length. Measured continuously with laser micrometer during slitting.
Doctor blade steel serves the entire printing and coating value chain — from narrow-web label printing to wide-web paper coating lines.
Chamber doctor blade systems on central impression (CI) and stack flexo presses. Ink metering on anilox rollers for corrugated, flexible packaging, labels, and carton printing. C100S is the industry default; 420J2 for water-based inks.
Doctor blades for engraved gravure cylinders in publication, packaging, and decorative printing. The blade wipes excess ink from the cylinder surface, leaving ink only in the engraved cells. 95Cr1 recommended for aggressive solvent inks.
Trailing blades and metering blades for paper coating machines. Controls clay coating, starch, and pigment layer thickness on fine papers and packaging boards. Thicker blades (0.25–0.30mm) typical.
Lamination adhesive metering, lacquer coating, and silicone release coating applications. Also used in digital printing pre-coat and primer stations. 420J2 preferred for aqueous systems in food-safe packaging.
We focus on what blade converters and printers actually need: the right grade, in stock, slit to width, shipped fast.
Our most-requested doctor blade spec is always in stock as master coils. Ready for slitting to your width immediately — no minimum order on slit coils.
Stock material ships within 3–5 working days after slitting. Custom heat treatment specs: 10–15 working days. Sample pieces available in 48 hours.
We support the small-batch, high-frequency reorder model that blade converters need. No punitive small-order surcharges. Order what you need, when you need it.
| Grade | Thickness (mm) | Master Width (mm) | Hardness (HV) | Surface | Status |
|---|---|---|---|---|---|
| C100S | 0.154 | 176 | 580–620 | White polished | In Stock |
| C100S | 0.20 | 176 | 580–620 | White polished | In Stock |
| 95Cr1 | 0.15 | 176 | 590–630 | White polished | Made to Order |
| 420J2 | 0.15 | 176 | 500–560 | Mirror polished | Made to Order |
| 420J2 | 0.20 | 176 | 500–560 | Mirror polished | Made to Order |
Slit widths from 10mm to 176mm. Edge trimming and deburring included. Other thicknesses (0.25mm, 0.30mm) available on request with 10–15 day lead time.
Doctor blade steel is supplied to EN 10132-4 tolerance classes. Our standard supply is T2 class for thickness and W1 class for width — tighter than most competitors' default.
| Thickness (mm) | T1 | T2 | T3 | T4 | T5 |
|---|---|---|---|---|---|
| 0.020–0.040 | ±0.002 | ±0.003 | ±0.004 | ±0.005 | ±0.008 |
| 0.040–0.080 | ±0.003 | ±0.004 | ±0.006 | ±0.008 | ±0.012 |
| 0.080–0.150 | ±0.004 | ±0.006 | ±0.008 | ±0.012 | ±0.018 |
| 0.150–0.300 | ±0.005 | ±0.008 | ±0.012 | ±0.016 | ±0.024 |
| 0.300–0.600 | ±0.008 | ±0.012 | ±0.016 | ±0.024 | ±0.035 |
| 0.600–1.000 | ±0.010 | ±0.016 | ±0.022 | ±0.030 | ±0.040 |
| 1.000–1.600 | ±0.014 | ±0.020 | ±0.028 | ±0.036 | ±0.050 |
| 1.600–2.500 | ±0.018 | ±0.026 | ±0.035 | ±0.045 | ±0.060 |
| Width (mm) | W1 | W2 | W3 |
|---|---|---|---|
| ≤ 25 | ±0.05 | ±0.10 | ±0.15 |
| 25–50 | ±0.08 | ±0.15 | ±0.25 |
| 50–100 | ±0.10 | ±0.20 | ±0.35 |
| 100–200 | ±0.15 | ±0.30 | ±0.50 |
| 200–300 | ±0.20 | ±0.40 | ±0.60 |
Tell us your grade, thickness, width, and quantity. We will respond within 4 hours with pricing, availability, and lead time.