Tempering is the heat-treatment step that determines whether a shear holds its edge or fails on you mid-career. It's the process that balances hardness against flexibility in the steel, and it's the single biggest factor separating a shear that stays sharp for months from one that chips, rolls, or snaps under normal salon use.
What Tempering Actually Does
Tempering is a controlled heat-treatment cycle: the steel is heated to a specific temperature, held there briefly, then cooled at a controlled rate. Manufacturers often repeat this cycle to relieve internal stress in the metal and lock in a specific balance between hardness and flexibility.
Skipping or rushing this step is one of the most common ways cheap shears fail. Under-tempered steel is brittle and chips at the edge; over-tempered (or untempered) steel is too soft and dulls almost immediately.
Why It Matters on the Floor
- Edge retention: Properly tempered steel stays sharp longer, meaning fewer trips to the sharpener and less mid-week performance drop-off.
- Stress resistance: Reduces the risk of cracking or chipping under the repetitive pressure of daily cutting.
- Flexibility without brittleness: The blade can flex slightly under pressure instead of snapping.
- Lifespan: A well-tempered shear, properly maintained, can outlast several cheaper pairs.
Rockwell Hardness: What the Numbers Mean
Most professional-grade hair shears fall between 58–62 HRC (Rockwell Hardness C-scale) — the sweet spot manufacturers target for durability without sacrificing edge stability.
| Hardness Range | Behavior |
|---|---|
| Above 62 HRC | Very hard edge, but increased risk of chipping and brittleness |
| 58–62 HRC | Target range for professional shears — durable and edge-stable |
| Below 58 HRC | Softer steel, dulls faster and needs more frequent sharpening |
Japanese steels like VG-10 and ATS-314 are popular in professional shears largely because their alloy composition responds predictably to tempering, making it easier for manufacturers to hit a consistent hardness target across a production run — which matters more than any single spec number.
Material Factors That Affect Tempering
Common Steel Types in Professional Shears
| Steel Type | Key Alloying Elements | Strengths |
|---|---|---|
| VG-10 | Molybdenum, vanadium, cobalt | Strong edge retention, good corrosion resistance |
| ATS-314 | High carbon, chromium | Greater hardness, strong wear resistance |
| Standard stainless | Basic chromium alloy | Decent durability and corrosion resistance at a lower cost |
High-purity alloys with tightly controlled compositions simply respond more predictably to heat treatment. That predictability is what lets a manufacturer produce a shear that meets spec, batch after batch — it's a manufacturing quality signal as much as a materials one.
Balancing Hardness and Flexibility
Every steel formulation is a trade-off. Push hardness too high and you get an edge that's sharp out of the box but chips the first time it hits a bobby pin or gets torqued during a slide cut. Keep it too soft and the edge rolls over within weeks. The 58–62 HRC range exists because it's where most steels hold both properties reasonably well.
Tempering's Impact on Performance and Lifespan
Edge Retention
Properly tempered shears hold their edge noticeably longer than untempered or poorly tempered steel, because the heat-treatment process stabilizes the steel's internal structure rather than leaving it prone to micro-fracturing at the edge. In practice, that means longer stretches between professional sharpenings and more consistent cutting performance day to day.
Resistance to Wear and Corrosion
Tempering also improves a shear's resistance to rust, chemical exposure, and misalignment — all things a working shear deals with constantly given hair product residue, moisture, and repeated use. Steels alloyed with chromium and manganese pair particularly well with tempering for this reason, since the heat treatment reinforces the corrosion resistance those elements already provide.
Tempering isn't a substitute for maintenance, though. Even a well-tempered shear needs regular care to actually deliver on its designed lifespan.
Maintaining Tempered Shears
Daily and Weekly Care
- Wipe blades down with a soft, lint-free cloth after every client to remove hair, moisture, and product residue.
- Avoid harsh chemicals (bleach, strong disinfectants) that can degrade the protective finish applied during manufacturing.
- Oil the pivot area and blades roughly twice a week to reduce friction and keep the action smooth.
- Store shears in a dedicated case rather than a loose drawer or pocket — humidity and incidental impact are two of the fastest ways to undo good tempering.
Professional Sharpening
High-quality tempered shears typically need professional sharpening every 6–12 months depending on how heavily they're used. Choose a sharpener who specifically works with tempered steel — incorrect technique (excess heat from a poorly maintained wheel, wrong angle, etc.) can undo the benefits of the original heat treatment and shorten the shear's working life. Expect to pay roughly $35–$75 per sharpening from a reputable service, which is a small cost relative to replacing the shear outright.
| Maintenance Task | Frequency | Purpose |
|---|---|---|
| Basic cleaning | After each use | Remove debris and moisture |
| Oiling | Weekly | Prevent buildup and ensure smooth operation |
| Professional sharpening | Every 6–12 months | Maintain the cutting edge |
What to Look For When Evaluating Shears
Since tempering has such a direct effect on how a shear performs and how long it lasts, it's worth evaluating a manufacturer's process, not just the steel type on the spec sheet. When comparing options, look at:
- Material quality: Steels like VG-10 or ATS-314 have a track record for durability and edge retention in professional use.
- Manufacturing consistency: A brand that can reliably hit a target hardness across production runs is a better bet than one with inconsistent quality control.
- Warranty coverage: A real warranty is a sign the manufacturer trusts their own tempering process.
- Access to maintenance services: Brands that offer or recommend qualified sharpening services make it easier to keep shears performing at their best over the long term.
Bottom Line
Tempering is what turns a piece of good steel into a reliable working tool. It's not the only thing that matters when choosing shears, but it's one of the least visible — and most consequential — factors in how long a pair will actually hold up in daily professional use. Combined with consistent care and regular professional sharpening, well-tempered shears are a genuine long-term investment rather than a recurring expense.
Ready to compare options? Browse Shihan Shears' full range of hair cutting shears to find a pair built with the steel quality and tempering process professional work demands.