Why HSS Material Names Are Confusing

Industrial buyers often ask whether a Chinese HSS material name is the same as AISI M2, AISI M35, DIN 1.3343 or JIS SKH51. The answer depends on the exact grade, heat treatment, supplier specification and chemical composition range.

For circular saw blades, the material name is important, but it is only the first step. Blade performance also depends on hardness, tooth geometry, coating, tensioning, flatness, runout, coolant condition and the cutting machine.

Common HSS Saw Blade Material Name Comparison

Common blade material name International reference often used Typical buying note
HSS W5 Domestic tungsten-molybdenum HSS naming; confirm by composition sheet Often used as an economical HSS option. Do not treat the name alone as a full international standard.
HSS-DMo5 DIN 1.3343 / AISI M2 / JIS SKH51 A common M2-class HSS material for general metal cutting saw blades.
HSS Co 2% / M2 + Co M2-based HSS with cobalt addition; exact standard should be confirmed Used when the buyer wants better red hardness than standard M2 but not the full cobalt level of M35.
HSS Co 5% DIN 1.3243 / AISI M35 / JIS SKH55 Cobalt HSS option for more demanding cutting conditions, heat resistance and harder materials.

Typical Chemical Composition Reference

The values below are practical reference values from a supplier comparison sheet. Final acceptance should always follow the agreed material certificate or production specification.

Grade C Si Mn Cr Mo V W Co
HSS W5 0.9 0.9 0.3 4.1 1.6 0.9 4.6 –
HSS-DMo5 / M2 / SKH51 0.9 0.25 0.3 4.1 5.0 1.8 5.4 –
HSS Co 2% / M2 + Co 0.9 0.4 0.3 4.1 5.0 1.9 6.4 2.01
HSS Co 5% / M35 / SKH55 0.9 0.4 0.3 4.1 5.0 1.9 6.4 4.8

Factory Composition Control Range Reference

For production control, steel grade is usually managed as an allowed range rather than a single number. The following table summarizes common HSS and HSS-related grades from our internal material composition reference. It helps buyers understand why a quotation should mention the exact material family instead of only saying “HSS”.

Material C Si Mn P S Cr V Mo W Co
W6 0.83-0.87 0.30-0.40 0.20-0.40 ≤0.03 ≤0.02 3.80-4.00 1.70-1.90 4.50-4.70 5.50-6.00 –
W5 0.92-0.96 0.80-1.20 0.20-0.40 ≤0.03 ≤0.02 3.80-4.00 0.90-1.20 1.40-1.70 4.60-4.90 –
W5 + Co 0.92-0.96 0.80-1.20 0.20-0.40 ≤0.03 ≤0.02 3.70-4.50 0.90-1.40 1.60-2.10 4.60-5.00 1.80-2.20
W4 / 4341 0.88-0.98 0.50-1.00 0.20-0.40 ≤0.03 ≤0.03 3.50-4.20 0.60-0.95 2.50-3.50 3.50-4.30 –
W3 0.90-1.05 1.00-1.30 0.20-0.40 ≤0.03 ≤0.03 4.10-4.40 1.10-1.30 1.70-2.00 2.70-3.00 –
W2 0.80-0.90 0.30-0.40 0.20-0.40 ≤0.03 ≤0.03 3.50-4.00 0.65-1.10 0.70-1.20 1.50-2.20 –
W18 0.78-0.85 0.30-0.40 0.30-0.40 ≤0.03 ≤0.03 3.60-4.20 0.65-1.00 – 17.50-18.20 –
M2 0.83-0.85 0.30-0.40 0.20-0.40 ≤0.03 ≤0.03 3.80-4.20 1.80-2.10 4.80-5.20 5.80-6.20 –
M35 0.90-0.98 0.30-0.40 0.30-0.40 ≤0.03 ≤0.03 3.80-4.20 1.80-2.10 4.80-5.20 5.80-6.20 4.50-5.20
M2 + 2Co
China local M42		 0.91-0.95 0.30-0.40 0.20-0.40 ≤0.03 ≤0.03 3.80-4.20 1.80-2.10 4.80-5.20 5.80-6.20 1.80-2.20
High Co M42 1.00-1.15 0.30-0.60 0.30-0.40 ≤0.03 ≤0.03 3.50-4.50 0.95-1.35 9.00-10.00 1.15-1.85 7.58-8.50
M5 0.80-0.85 0.50-0.70 0.30-0.40 ≤0.03 ≤0.03 3.90-4.10 1.20-1.50 2.30-2.70 5.40-6.00 –
DF9 0.92-0.96 0.80-1.20 0.20-0.40 ≤0.03 ≤0.03 3.80-4.00 1.20-1.60 2.70-3.20 4.60-4.90 1.80-2.20
Mainstream HSSM2, M35, W6 and W18 are easier to explain in export communication when paired with certificate wording.
Economical HSS familyW5, W4 / 4341, W3 and W2 should not be treated as direct substitutes for M2 or M35 without confirming the cutting condition.
Cobalt-added gradesW5 + Co, M35, M2 + 2Co (China local M42), High Co M42 and DF9 need exact certificate wording when heat resistance is part of the buyer requirement.

Materials That Should Not Be Mixed Up With HSS

The same material reference file also lists tool steel or stainless steel grades such as 811, Cr8, D2D, Cr12MoV, 9Cr18Mo and CYS. These names may appear in cutting-tool or knife discussions, but they are not the same purchasing category as M2 or M35 HSS circular saw blades.

For export inquiries, it is safer to separate the question into three layers: blade body material, cutting edge material and coating. HSS blades are one family; cermet-tipped saw blades, TCT carbide-tipped saw blades and solid carbide knives follow different material logic.

What The Main Elements Usually Mean

Carbon CSupports hardness and cutting edge strength after heat treatment.
Chromium CrImproves hardenability and contributes to wear resistance.
Molybdenum MoImportant for hot hardness and toughness in M-series HSS.
Vanadium VForms hard carbides and improves wear resistance, but grinding quality must be controlled.
Tungsten WImproves red hardness and high-temperature cutting stability.
Cobalt CoImproves hot hardness and heat resistance, useful in harder or hotter cutting conditions.

M2-Class HSS Or M35-Class HSS: Which One Should Buyers Choose?

M2-class HSS, including the commonly referenced DIN 1.3343 / AISI M2 / JIS SKH51 family, is widely used for general-purpose HSS circular saw blades. It is suitable for many steel, stainless steel, copper, aluminum and non-ferrous cutting applications when the machine, tooth geometry and coating are correct.

M35-class HSS, often referenced as DIN 1.3243 / AISI M35 / JIS SKH55, contains cobalt and is usually selected when cutting heat is higher, material is more demanding, or the buyer wants better edge retention under tougher conditions. However, M35 is not automatically better for every job. A wrong tooth pitch or unstable machine can still break an expensive cobalt HSS blade.

Why The Same Grade Can Perform Differently

Two blades both called M2 or M35 can perform differently because saw blade production is not only material purchasing. The following items should be checked together:

  • Heat treatment and final hardness range.
  • Plate flatness, runout and tensioning.
  • Tooth geometry, rake angle, relief angle and tooth pitch.
  • Coating choice such as bright, VAPO, TiN, TiCN or TiAlN.
  • Machine rigidity, clamping, coolant and feed control.

How To Specify HSS Material In An Inquiry

When sending an HSS circular saw blade inquiry, it is better to provide both the material name and the intended cutting condition. This avoids misunderstanding between domestic material names and international standards.

Inquiry item Example Why it helps
Material requirement M2 / SKH51 / DMo5 or M35 / SKH55 / Co 5% Confirms the grade family before production.
Blade size OD, thickness, bore, kerf and tooth count Controls machine fit and cutting stability.
Workpiece Steel tube, stainless tube, copper bar, aluminum profile Determines tooth pitch, coating and cutting parameters.
Cutting problem Burr, blue marks, short life, broken teeth or rough surface Shows whether the issue is material, coating, tooth form or machine condition.
Required certificate Material certificate, hardness report or inspection record Important for repeat orders and quality tracking.

Practical Recommendation

If the buyer only says “HSS blade”, the specification is still incomplete. For a stable repeat order, record the material grade, coating, blade size, tooth geometry, machine model, cutting material and actual trial result.

For most general metal cutting applications, M2-class HSS is a practical starting point. For harder materials, higher heat or more demanding production targets, M35-class cobalt HSS may be considered after confirming that the machine and tooth design are suitable.

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