A reciprocating saw blade flexes 3,000 times a minute and cannot break. A grinding wheel base runs at 100 m/s and cannot wobble. A chuck spring cycles every bit change and cannot fatigue. Five steel families, each tuned to the specific failure mode of the part it becomes.
A reciprocating saw blade fails by fatigue fracture at the tang. A grinding wheel base fails by runout vibration from poor flatness. A chuck spring fails by loss of spring force from fatigue. A utility knife fails by edge dulling. A motor housing fails by cracking during deep drawing. Each failure mode demands a different steel, and the five families below are how power tool engineers match material to failure mode.
C ~0.80%, Cr ~0.50%, W ~0.20%. The Japanese alloy tool steel purpose-built for reciprocating and jigsaw blades. The chromium and tungsten refine the quench structure and add toughness without sacrificing hardness — after Q&T it reaches 50–55 HRC and survives ≥100,000 cycles at 2,000–3,000 strokes per minute. Plain carbon SK5 would be harder but brittle; SKS51 is the compromise that stays sharp and does not snap.
Choose SKS51 for every reciprocating and jigsaw blade.C 0.72–0.80%, Cr 0.30–0.60%. The European alloy tool steel standard for grinding wheel bases and cutting disc centers. Chromium provides through-hardening and dimensional stability in 1.0–2.0 mm disc sections. Flatness ≤0.10 mm is non-negotiable — a wavy base causes the abrasive layer to bond unevenly, and the wheel vibrates at 80–120 m/s surface speed, causing poor cut quality and premature wheel failure.
Choose 75Cr1 for grinding wheel bases and cutting disc centers.C 0.80–0.90% (SK5) / 0.60–0.70% (SK7). Carbon tool steel for utility knife blades, wood chisels and scraping blades where maximum edge hardness is the priority and impact loading is moderate. SK5 reaches 57–60 HRC for long edge life on utility knife snap-off blades; SK7 trades a little hardness for toughness on chisels and impact-duty cutting tools.
Choose SK5 for utility knives, SK7 for chisels and impact blades.65Mn (C 0.62–0.70%, Mn 0.90–1.20%) for chuck springs, retaining rings and jaw springs at 42–48 HRC — the manganese provides hardenability and a high elastic limit for spring components that cycle thousands of times. SPCC (C ≤0.12%) for motor housings and gear boxes at 1.0–2.5 mm — low carbon cold-rolled strip that deep-draws into complex housing geometry, welds cleanly, and takes a cosmetic powder-coat finish.
Choose 65Mn for springs, SPCC for housings and gear boxes.Indicative values from production power tool programs; the final spec is agreed at RFQ against your component drawing, tool class and governing standard.
| Component | Steel grade | Thickness | Key parameter |
|---|---|---|---|
| Reciprocating saw blade | SKS51 | 0.9 – 1.5 mm | HRC 50–55, fatigue ≥100,000 cycles, width 19–32 mm |
| Jigsaw blade | SKS51 | 0.9 – 1.2 mm | HRC 50–55, fatigue ≥100,000 cycles, width 6–10 mm |
| Grinding wheel base | 75Cr1 | 1.0 – 2.0 mm | Flatness ≤0.10 mm, HRC 45–52, OD 100–230 mm |
| Cutting disc center | 75Cr1 | 1.0 – 1.6 mm | Flatness ≤0.10 mm, dimensional stability |
| Utility knife blade | SK5 | 0.5 – 0.7 mm | HRC 57–60, edge sharpness, snap-off notch geometry |
| Wood chisel / scraper | SK7 | 2.0 – 5.0 mm | HRC 55–58, impact toughness, edge retention |
| Drill chuck spring / retaining ring | 65Mn | 0.4 – 1.0 mm | HRC 42–48, spring force, fatigue resistance |
| Impact drill piston | 65Mn / SAE1078 | 2.0 – 4.0 mm | HRC 45–50, impact toughness, wear resistance |
| Motor housing / gear box | SPCC | 1.0 – 2.5 mm | Deep-drawable, weldable, cosmetic surface |
| Electric wrench socket | 40Cr / 42CrMo | 3.0 – 6.0 mm | HRC 38–45, torque resistance, impact toughness |
Reciprocating blade fatigue life is verified by the blade maker's endurance rig; the strip contributes uniform hardness, clean microstructure and controlled decarb. Grinding wheel base flatness is confirmed per production lot. For high-volume blade programs, specify the hardness band and fatigue target at RFQ.
All grades supplied with confirmed mechanicals and MTC per coil. Choose by component function, failure mode and tool class (consumer vs. professional).
| Component type | Primary grade | Alternative grade | Selection criterion |
|---|---|---|---|
| Reciprocating saw blade (pro) | SKS51 | SKS5 / 75Cr1 | Fatigue life ≥100K cycles + edge hardness |
| Reciprocating saw blade (consumer) | SK5 | SAE1078 | Cost vs. fatigue life trade-off |
| Jigsaw blade (wood/metal) | SKS51 | SK5 (bi-metal backing) | Backing toughness + HSS tooth weldability |
| Grinding wheel base | 75Cr1 | SAE1075 / 65Mn | Flatness ≤0.10 mm + dimensional stability |
| Cutting disc center | 75Cr1 | SPCC (low-speed discs) | Surface speed rating + bond compatibility |
| Utility knife snap-off blade | SK5 | SK7 / SAE1078 | Edge hardness HRC 57–60 + snap-off notch strength |
| Wood chisel / cold chisel | SK7 | SKS51 / 60Si2Mn | Impact toughness + edge retention |
| Drill chuck spring / circlip | 65Mn | C67S / SAE1074 | Spring force + fatigue through bit-change cycles |
| Impact drill piston / ram | 65Mn | SAE1078 / 50CrV4 | Impact toughness + wear at HRC 45–50 |
| Angle grinder gear | 20CrMnTi | 40Cr (carburized) | Surface hardness + core toughness |
| Motor housing / gear box | SPCC | SPHC / SPCD | Draw depth + weldability + paint surface |
| Electric wrench socket | 40Cr | 42CrMo | Torque resistance + impact toughness |
Bi-metal reciprocating and jigsaw blades use SKS51 or SK5 as the backing strip with high-speed steel (M42/M2) teeth electron-beam welded to the edge — the backing grade is selected for fatigue toughness, not edge hardness. Confirm whether your blade is all-hard or bi-metal at RFQ.
These are the failure modes that show up in power tool production, in the order tool engineers care about them.
The dominant reciprocating blade failure: a fatigue crack starts at the tang hole or notch root and propagates across the blade after a few thousand strokes. Fix: SKS51 alloy tool steel with chromium and tungsten for toughened martensite, controlled hardness at 50–55 HRC (not harder), and clean blanked edges at the tang. The strip contributes uniform hardness and low decarb so the fatigue strength is consistent blade to blade.
A wheel base that is not flat to ≤0.10 mm causes the abrasive layer to bond unevenly — the wheel runs eccentric at 80–120 m/s, vibrating the tool, producing a poor cut surface, and failing the wheel balance test. Fix: 75Cr1 strip supplied with controlled flatness, blanked with uniform die clearance, and stress-relieved before abrasive bonding. We confirm incoming flatness per coil and can supply ground-flat strip for critical wheel programs.
A chuck spring that loses its force after repeated bit changes fails to hold the bit securely — a safety issue in impact tools. Fix: 65Mn spring steel with adequate manganese for through-hardening in 0.4–1.0 mm sections, tempered to 42–48 HRC for the optimal spring force vs. fatigue compromise, and shot-peened on the customer side for residual compressive stress. We confirm hardness and tensile properties per coil.
A motor housing that cracks at the bearing pocket or mounting boss during deep drawing causes scrap and line downtime. Fix: SPCC in the correct temper (fully annealed or skin-passed) with confirmed elongation and plastic strain ratio (r-value). For deep gear box housings, SPCD or SPCE may be specified over SPCC. We confirm mechanicals per coil and can supply trial coils for draw testing before production commitment.
Power tool production draws on multiple steel families. Match your component below and confirm at RFQ.
SKS51 / SK5 / SK7 carbon and alloy tool steel for reciprocating blades, utility knives and chisels — the core of this page. Tool steel family →
SAE1078 / 75Cr1 / 65Mn for grinding wheel bases, impact pistons and consumer-grade blades where hardenability and cost are balanced. High carbon family →
65Mn / C67S / 50CrV4 for chuck springs, retaining rings and impact components requiring spring force and fatigue resistance. Spring steel family →
SPCC / SPCD low carbon cold-rolled strip for motor housings, gear boxes and structural tool components requiring deep drawability and weldability. Cold-rolled family →
A typical 150 mm wood-cutting reciprocating saw blade, described the way it runs.
The blade is 150 mm long, 19 mm wide, 1.2 mm thick, with a universal tang (12.7 mm width, 6.3 mm pin hole) at one end and 6 TPI wood-cutting teeth ground along the other edge. The drawing calls SKS51 alloy tool steel strip, 1.2 × 20 mm coil, spheroidized, flatness ≤0.15 mm/m, decarb ≤0.03 mm per side. The coil is blanked — progressive die for the tang profile and tooth roughing — then the blades go through austenitizing at 820–850 °C, oil quenching, and tempering to 52–54 HRC. After hardening, the teeth are ground to a 30° included angle with a 0.05 mm edge hone, the tang is deburred, and the blade is coated (black oxide or PTFE for wood blades) and packaged.
The fatigue test is the moment of truth: every production lot is sampled and run in a test fixture at 2,800 strokes per minute against a standard wood workpiece until the blade breaks at the tang. The acceptance criterion is ≥100,000 cycles — a blade that breaks at 50,000 cycles fails the lot and triggers a material investigation. That fatigue life is inherited from the strip: its hardness uniformity, its decarb control, its carbide structure after spheroidizing, and its edge condition after blanking. If the strip has hardness scatter across the width, some blades will run too hard (brittle, break early) and some too soft (teeth dull, cut slowly). Our job is to make the SKS51 strip's hardness, decarb and microstructure so repeatable that the blade line's variables (blanking, hardening, grinding) are the only variables left.
The same tool uses a 75Cr1 grinding wheel base at 1.5 mm thickness with flatness ≤0.10 mm for the accessory cutting disc, and a 65Mn chuck spring at 0.6 mm thickness for the keyless blade clamp. Each component has its own steel, its own hardness band, and its own failure mode — and each requires a strip supplier that understands the specific parameter that matters for that part.
If your power tool program needs SKS51 for blades, 75Cr1 for wheel bases, SK5 for knives, 65Mn for springs, or SPCC for housings, send the component drawing and we confirm grade, key parameters and a trial-coil plan. Our slitting and processing services cover exact-width coils, cut-to-length blades and edge conditioning for progressive-die blanking.
Related reading: how spheroidizing annealing prepares SKS51 and SK5 strip for hardening and fatigue resistance, and how edge burr and shear quality affect reciprocating blade fatigue life at the tang. For procurement context, see our precision steel strip buyer's handbook.
These grade families share material, processing or application territory with the topic on this page.
SKS51 / SK5 / SK7 / T8A grades with wear resistance and toughness for reciprocating blades and knives.
65Mn / C67S / 50CrV4 grades with high elastic limit and fatigue resistance for power tool springs.
SAE1078 / 75Cr1 / 65Mn grades with hardenability and dimensional stability for wheel bases and impact parts.
Send component drawing, thickness × width, key parameter (HRC, fatigue, flatness), quantity and destination port. Our engineers reply within one working day with grade match and a trial-coil option.