Views: 0 Author: Site Editor Publish Time: 2025-06-12 Origin: Site
Ever wonder what those colored stripes on abrasive wheels mean? They’re not just for looks—they’re about safety. Each color shows a speed limit you must follow. Choosing the wrong one can cause serious accidents. In this post, you’ll learn what the color code for abrasive wheels means, why it matters, and how to use it right.
Color codes are painted stripes telling us how fast a wheel can safely spin.
They protect users from breakage and flying debris.These stripes aren’t decoration. They are speed-rating signals set by engineers.
You’ll usually find them on the wheel’s rim or printed label.
Some makers add a side stripe so it stays visible after mounting.The system follows BS EN 12413 and ISO 525.
That means a blue stripe in London means the same in Sydney.
Stripe Color | Max Speed (m/s) |
Blue | 50 |
Yellow | 60 |
Red | 80 |
Green | 100 |
Blue / Yellow | 125 |
Color stripes spell out one thing: how fast the rim can safely move. Below is the quick reference most workshops pin on the wall.
Color Stripe | Maximum Speed (m/s) | Common Use Cases |
Blue | 50 | Light-duty tools, basic grinding jobs |
Yellow | 60 | Everyday metal prep, moderate cuts |
Red | 80 | General industrial grinding and cutting |
Green | 100 | High-speed production or heavy stock removal |
Blue / Yellow | 125 | Ultra-fast precision finishing, aerospace parts |
Meters per second measure surface speed along the rim, not how many turns the spindle makes. RPM changes once diameter changes: a small 100 mm disc spins quicker than a 230 mm disc to hit the same 80 m/s. Always convert using the wheel size printed on the label before pressing the start button.
Ignore the stripe and the wheel can over-speed, over-heat, then shatter.
Fragments travel faster than a bullet, slicing skin, cables, even guards.
A factory in Leeds saw three hand injuries when a green-striped disc ran on a 125 m/s spindle.
HSE reports link hundreds of annual grinder accidents to mismatched color codes or unreadable labels.
● PUWER 1998: employers must supply equipment that stays within safe operating limits.
● PPE Regulations 1992: suitable eye, face, and hand protection is mandatory when wheels spin.
● Health and Safety at Work Act 1974: directors face prosecution if foreseeable hazards—like wrong color wheels—injure staff.
Color bands let operators confirm speed in seconds; no maths on the shop floor.
Supervisors walk by, glance at the stripe, compare to the machine’s chart, and sign off.
Color codes help with speed, but they’re just one part of a much bigger safety picture. Every abrasive wheel includes a range of other markings that give users crucial information about performance limits, usage restrictions, shape compatibility, and safety compliance. Ignoring these markings can lead to improper mounting, equipment damage, or even serious injury. Here’s what every operator and supervisor should understand when reading an abrasive wheel.
This alphanumeric sequence shows key technical details about the wheel. For example:
● WA = White aluminium oxide (abrasive type)
● 60 = Medium grit size
● K = Medium grade or hardness
● 7 = Structure level (porosity/density)
● V = Bond type (Vitrified, in this case)
Each part affects how the wheel cuts, resists heat, and wears over time. Choosing the wrong spec—especially grit or bond—can reduce tool life or damage the workpiece.
Every wheel has a clearly marked maximum operating speed, shown in two forms:
● Surface speed (in m/s)
● Rotational speed (in RPM)
Operators must ensure the machine's spindle speed doesn’t exceed these limits. For example, a wheel rated at 80 m/s and 8,500 RPM should never be mounted to a machine that spins faster than this, especially if the wheel is large, as RPM and m/s relate to the diameter.
Organic bonded wheels (like resin-based types) degrade over time. They carry a “USE BY” date, usually 3 years from the manufacturing date. Using an expired wheel increases the risk of failure under pressure. Always check this date before installation, especially if the wheel’s been stored for a long period.
Some abrasive wheels include arrows that show the correct direction of rotation. These are especially important when the wheel has an uneven mass or asymmetric reinforcement. Installing a wheel against its intended direction can result in poor performance, increased wear, or imbalance during operation.
These standard codes tell users what not to do with the wheel. For instance:
● RE1: Not for hand-held machines
● RE2: Not for hand-held cutting-off
● RE3: Not for wet grinding
● RE4: Not for side grinding
● RE5: Only for wet grinding
● RE6: Not permitted on manually guided machines
Operators must always match the RE code with their equipment and task. Misuse voids compliance and increases risk.
Every wheel has an ISO shape code that describes its profile and intended mounting setup:
● Type 1: Flat cutting wheel
● Type 27: Depressed-centre (grinding)
● Type 41/42: Cut-off wheels (flat or depressed)
Mounting the wrong type can interfere with machine guards or produce poor results. Guards and flanges must be compatible with the shape.
Each compliant wheel includes the manufacturer’s name or trademark, along with a test code or record. These details confirm the product passed quality checks under BS EN 12413 or ISO 525 standards. It's proof the wheel was designed, tested, and labeled correctly—and should be documented for legal and safety audits.
A wheel’s stripe gives speed, but its label hides the full story. Let’s decode one typical mark.
Segment | Meaning | Why it matters |
WA | White aluminium oxide abrasive | Tells cutting aggressiveness and spark pattern |
60 | Medium grit size | Controls finish and metal removal rate |
K | Medium-soft grade | Softer grades self-sharpen on hard metals |
7 | Open structure | Extra chip space, cooler grinding |
V | Vitrified bond | Rigid, heat-resistant, suits precision work |
BF | Reinforced resin (optional tag) | Adds strength for cut-off wheels |
41 | ISO Type 41 shape | Flat cut-off wheel for hand tools |
80 m/s | Max surface speed | Never exceed this or the wheel may burst |
Mandatory under BS EN 12413 / ISO 525
● Abrasive type, grit, grade, structure, bond
● Wheel diameter, thickness, bore (often nearby)
● ISO shape number
● Maximum operating speed in m/s (plus RPM for large wheels)
● Manufacturer name or trademark
● Test record or code for traceability
Variable or Situational Marks
● Reinforcement codes like BF or SR—only on resin wheels
● Expiry date—required on organic-bond wheels, not vitrified
● Restriction codes (RE1–RE6)—only when limits apply
● Mounting arrow—added when balance or weight distribution matters
Read every segment before mounting. The label tells you if the wheel truly fits the job, the machine, and the law.
Check the spindle’s rated RPM in the manual.
Locate the wheel’s color stripe, convert its m/s to RPM using diameter, and confirm the machine never exceeds that figure.
Stripe | Max m/s | Typical RPM on 230 mm disc |
Blue | 50 | ≈ 4 150 RPM |
Yellow | 60 | ≈ 4 980 RPM |
Red | 80 | ≈ 6 620 RPM |
Green | 100 | ≈ 8 280 RPM |
Blue/Yellow | 125 | ≈ 10 350 RPM |
● Flanges: clean, flat, same diameter.
● Blotters: paper washers stop stress cracks.
● Guards: adjust to shield the operator.
● PPE: EN 166 visor, gloves, dust mask when needed.
1. Visual inspection—look for chips, burns, loose grit.
2. Ring test—tap gently; a clear ring means no hidden cracks.
3. Label review—verify stripe, expiry date, ISO type, RE code.
4. Trial run—spin the wheel for 30 seconds in a cage before cutting.
Follow these steps every shift; they keep the color code meaningful and the shop floor safe.
Q1: Can I use a wheel with a higher color code on a slower machine?
A: Yes, as long as the machine’s speed does not exceed the wheel’s maximum rated speed.
Q2: Do all abrasive wheels have color stripes?
A: No, but wheels rated by BS EN 12413 or ISO 525 often include them for safety and quick identification.
Q3: What if the color code is faded or missing?
A: Do not use the wheel. If markings are unreadable, discard it to avoid unknown speed risks.
Q4: How is speed in m/s different from RPM?
A: m/s measures surface speed; RPM measures rotation rate. Conversion depends on wheel size.
Q5: Are color codes the same worldwide?
A: Yes, international standards like ISO 525 help maintain consistency across global markets.
The color code on abrasive wheels shows their maximum safe speed. Each stripe prevents accidents caused by over-speeding. Color coding helps match the right wheel to the right tool. It protects users and ensures legal compliance. Always read all markings before using a wheel. It’s a simple step that saves time, tools, and lives.
At Tianjin Pengyu New Materials Co., Ltd., we don’t just deliver high-performance abrasive wheels—we support you with the tools and knowledge to use them safely and efficiently. Download our free Abrasive Wheel Identification and Safety Guide to help your team choose the right wheel every time.
Have questions about product fit or legal requirements? Contact our expert technical support team for tailored solutions and free consultation.
