Hazards of Abrasive Wheels Flashcards
6 cards from real Abrasive Wheels Training Certificate practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Hazards of Abrasive Wheels flashcards as text
What is the primary cause of abrasive wheel burst, which is the most serious hazard?
Answer: Overspeed — operating the wheel above its maximum RPM rating causes centrifugal forces to exceed the bond's tensile strength
Wheel burst (disintegration) occurs when centrifugal forces generated by rotation exceed the tensile strength of the bonding material. The primary cause is operating above the maximum marked RPM. Other causes include mechanical damage, incorrect mounting, and side loading. Wheel fragments can reach lethal velocities.
What energy does a bursting abrasive wheel release, and why is this so dangerous?
Answer: Kinetic energy proportional to mass and the square of peripheral velocity; fragments can travel at several hundred metres per second
A 125mm angle grinder disc rotating at 11,000 RPM stores significant kinetic energy. When it bursts, fragments are propelled outward at high velocity — potentially hundreds of metres per second. The combination of mass and velocity gives fragments lethal penetrating power sufficient to pierce workwear and cause fatal injury.
What is the hazard of 'contact' with an abrasive wheel?
Answer: Severe laceration, degloving, or amputation from accidental contact with the rotating abrasive surface
Contact with a rotating abrasive surface causes immediate severe injury. The abrasive rapidly removes skin, tissue, and bone on contact. High-speed contact with a 125mm disc at 11,000 RPM causes injuries comparable to a high-speed circular saw — amputations and severe lacerations are common outcomes of unguarded wheel contact.
What type of vibration hazard is associated with extended use of angle grinders?
Answer: Hand-arm vibration syndrome (HAVS) causing permanent damage to blood vessels, nerves, and joints in the hands and arms
Hand-arm vibration syndrome (HAVS) — including vibration white finger (VWF) — is caused by prolonged exposure to hand-transmitted vibration from power tools including angle grinders. It is irreversible and progressive, causing permanent damage to peripheral blood vessels, nerves, and tendons, leading to pain, disability, and loss of tactile sensation.
What fire and explosion hazard is created by grinding sparks?
Answer: Sparks can travel several metres and ignite flammable materials, liquids, vapours, and combustible dusts in the vicinity
Grinding sparks are incandescent metal particles at temperatures of several hundred to over 1,000°C. They can travel 3–10 metres from the grinding point and ignite flammable liquids, gases, vapours, combustible dusts, and dry materials such as wood shavings and insulation. A hot work permit system manages this risk.
What health hazard is caused by inhaling grinding dust and fume?
Answer: Respiratory diseases including occupational asthma, fibrosis, and metal fume fever depending on the workpiece material
Grinding fumes and dust include metal particles, metal oxides (including hexavalent chromium from stainless steel — a known carcinogen), non-metallic abrasive dust, and bonding material. Inhalation can cause occupational asthma, metal fume fever, lung fibrosis, and occupational cancer. LEV (local exhaust ventilation) and RPE are required controls.