High carbon strip that blanks into a blade body, hardens flat to 42–48 HRC, and stays true through the furnace — with the decarb and flatness numbers controlled on paper, not by luck.
The body of a circular saw does three jobs at once: it transmits torque to the rim, it holds the plate flat against centrifugal and cutting loads, and it stays tough at the gullets where cracks like to start. High carbon strip in the 0.8–2.5 mm band is the material that balances those three, and the three grades below are how blade makers tune the balance.
C 0.72–0.85%. The most widely used body steel for wood-cutting and general-purpose blades: hardens to the 42–48 HRC band with good toughness, blanks cleanly in the spheroidized condition, and is forgiving to tension.
Default choice for most blade bodies.The Japanese carbon tool steel (C 0.80–0.90%) commonly specified for thin-gauge and premium blades. Slightly harder and more wear-resistant than 1078 at the same temper, at the cost of a little toughness.
Choose SK5 for thin premium bodies and finer cuts.The European 75Cr1 (C 0.72–0.80% + Cr) is a standard saw blade steel in EN practice. The chromium improves hardenability and quench response on thin sections, which tightens the hardness band across the plate.
Choose 75Cr1 when hardness uniformity across the body is the fight.Indicative values for blade body programs; the final spec is agreed at RFQ against your blade size, cutting duty and governing standard.
| Parameter | Typical value | Why it matters |
|---|---|---|
| Strip thickness | 0.8 – 2.5 mm | Thin blades for fine cuts; thick bodies for heavy ripping and demolition |
| Delivery condition | Spheroidized (soft annealed) | Blanks cleanly; hardens predictably to the body hardness target |
| Finished body hardness | 42 – 48 HRC (after customer Q&T) | Holds plate shape and tension; stays tough at the gullets |
| Flatness | ≤ 0.15 mm/m (before blanking) | Flat strip in = flat blade out; wavy strip cannot be tensioned true |
| Decarburization | ≤ 0.03 mm per side (controlled anneal) | A decarburized skin softens the tooth seats and cracks in service |
| Surface finish | Clean, scale-free, oiled or dry per order | Blanking, laser cutting and marking all want a consistent surface |
| Width / coil form | Slit to your body-blanking width | Progressive blanking and laser nesting both want exact strip width |
| MTC | Chemistry + mechanicals per heat | Traceability for blade certification and customer audits |
Hardness, flatness and decarb are agreed per order and verified on the inspection report. For hardened-and-tempered delivery (thin-gauge blades), the HRC band is confirmed per coil.
All supplied spheroidized as standard, H&T on request. The choice is blade size, gauge, and whether you are on an AISI, JIS or EN drawing standard.
| Grade | Typical C % | Why it is specified | Typical blade use |
|---|---|---|---|
| SAE1078 | 0.72 – 0.85 | Balanced hardenability, toughness and cost; the default body steel | Wood, general-purpose and most carbide-tipped bodies |
| SK5 (JIS) | 0.80 – 0.90 | Higher carbon ceiling for edge and wear on thin sections | Thin premium bodies, fine-cut and panel blades |
| 75Cr1 (EN) | 0.72 – 0.80 + Cr | Chromium for tighter quench response and hardness uniformity | EU-spec bodies, large-diameter plates |
| SAE1074 | 0.68 – 0.75 | Slightly leaner than 1078 for maximum toughness on impact-duty blades | Demolition and metal-cutting bodies |
| C75S (EN 10132-4) | 0.70 – 0.80 | European spring/blade strip grade; near-equivalent of SAE1074–1078 | EU-spec thin bodies and springs in the same line |
Chemistry shown is the typical band for each grade; confirm the delivered heat on the MTC. C75S values are indicative of the EN 10132-4 family — refer to the latest revision of the standard for the governing limits.
The body is the least glamorous part of a saw blade and the one that fails most publicly. These are the failure modes and what we control on the strip.
Strip with internal flatness scatter comes out of the quench furnace with permanent wave. Fix: tight flatness on the delivered strip (≤ 0.15 mm/m) and uniform gauge so the quench cools the plate symmetrically.
A decarburized layer under-hardens; tooth seats soften and the gullet cracks in service. Fix: controlled-atmosphere spheroidizing with measured decarb ≤ 0.03 mm per side, reported on the certificate.
If chemistry varies coil to coil, the temper response varies and the body hardness band widens. Fix: consistent heats with documented chemistry; 75Cr1 when you need the chromium to tighten the quench response.
Cracks start at the gullet radius under cyclic loading. Fix: toughness comes from the 42–48 HRC band and clean shear edges in blanking; the strip contributes with a carbide structure that is fine and uniform after spheroidizing.
Blade production draws on several steel families. Match your product below and confirm at RFQ.
SAE1078 / SK5 / 75Cr1 spheroidized strip for the body — the core of this page. SAE1078 strip →
For all-hard blades and thin stock removal blades, higher-carbon tool strip holds the cutting edge without carbide teeth. Tool steel family →
Some thin-gauge and specialty blades are made from spring strip grades for extra toughness. Spring steel family →
A typical 350 mm carbide-tipped blade body, described the way it runs.
The body is a 350 mm disc, 2.2 mm thick, with a 30 mm bore and a laser-cut tooth profile around the rim. The drawing calls SAE1078 strip, 2.2 × 360 mm coil, spheroidized, flatness ≤ 0.15 mm/m, decarb ≤ 0.03 mm per side. The coil is blanked — laser for the profile, or a blanking die where volume justifies it — then the bodies go through austenitizing, press or roller quenching, and tempering to 44–46 HRC.
After hardening, the bodies are tensioned: a skilled operator hammers or rolls controlled stress into the plate so it runs true at speed, then the tooth seats are ground, carbide tips brazed, and the blade balanced. Every failure mode in that sequence — wave, soft seats, scatter, gullet cracks — traces back to the strip that went into the furnace. Our job is to make the strip's flatness, decarb and hardness response so repeatable that the blade line's variables are the only variables left.
If your blade sits in the 0.8–2.5 mm high carbon envelope, send the drawing and we confirm grade, flatness, decarb limit and a trial-coil plan.
Related reading: how decarburization is controlled on annealed high-carbon strip, and what spheroidizing annealing actually does to carbide structure.
These grade families share material, processing or application territory with the topic on this page.
SAE1078 / 65Mn / SK5 grades for hardened parts, springs and cutting edges.
SK5 / SK7 / T8A / T10A grades with wear resistance and edge hardness for cutting tools.
65Mn / 50CrV4 / 60Si2Mn grades with high elastic limit and fatigue resistance.
Send thickness × width, blade diameter, quantity and destination port. Our engineers reply within one working day with grade match, flatness/decarb confirmation and a trial-coil option.