Torque wrench types | Torque wrench tolerance | |||
---|---|---|---|---|
Type | Class | Description | ≤ 10 Nm | >10 Nm |
Type 1: Indicating | Class A | Wrench with torsion or flexing bar | ±6% | |
Class B | Wrench with rigid body and indicator | ±6% | ±4% | |
Class C | Wrench with rigid body and electronic measurement | ±6% | ±4% | |
Class D | Screwdriver with indicator | ±6% | ||
Class E | Screwdriver with electronic measurement | ±6% | ±4% | |
Type 2: Setting | Class A | Adjustable wrench with indicator | ±6% | ±4% |
Class B | Fixed torque wrench | ±6% | ±4% | |
Class C | Adjustable wrench without indicator | ±6% | ±4% | |
Class D | Adjustable screwdriver with indicator | ±6% | ||
Class E | Fixed screwdriver | ±6% | ||
Class F | Adjustable screwdriver without indicator | ±6% | ||
Class G | Adjustable wrench with flexing bar and indicator | ±6% |
Torque wrench types | Torque wrench tolerance | |||
---|---|---|---|---|
Type | Class | Style | <20% max rating | 20-100% max rating |
Type 1: Indicating | Class A: Deflecting beam | Style 1: Plain scale | ±0.8% | ±4% |
Style 2: Scale with signal | ||||
Style 3: Scale with memory | ||||
Class B: Deflecting beam, changeable head | Style 1: Plain scale | |||
Style 2: Scale with signal | ||||
Style 3: Scale with memory | ||||
Class C: Rigid housing | Style 1: Plain scale | |||
Style 2: Scale with signal | ||||
Style 3: Scale with memory | ||||
Class D: Rigid housing, changeable head | Style 1: Plain scale | |||
Style 2: Scale with signal | ||||
Style 3: Scale with memory | ||||
Class E: Screwdriver, indicating | Style 1: Plain scale | |||
Style 2: Scale with signal | ||||
Type 2: Setting[note 1] | Class A: With graduation | Style 1: Without ratchet | ±0.8% | ±4% |
Style 2: With ratchet | ±0.8% | ±4% | ||
Style 3: Changeable head | ±0.8% | ±4% | ||
Style 4: Flexible head with ratchet | See standard | |||
Class B: Without graduation | Style 1: Without ratchet | ±0.8% | ±4% | |
Style 2: With ratchet | ±0.8% | ±4% | ||
Style 3: Changeable head | ±0.8% | ±4% | ||
Style 4: Flexible head with ratchet | See standard | |||
Type 3: Limiting | Class A: Screwdriver | Style 1: Without graduation | ±1.2% | ±4% |
Style 2: With graduation | ||||
Class B: T handle | Style 1: Without graduation | |||
Style 2: With graduation |
Type | Class | Pre-calibration | Calibration procedure |
---|---|---|---|
Type 1 | All classes | Preload once at the highest certified value | 5 measurements in a row for all values |
Type 2 | Class A | Preload five times at the highest certified value | 5 measurements in a row for all values |
Class B | 5 measurements at nominal value | ||
Class C | 10 measurements in a row for all values | ||
Class D | 5 measurements in a row for all values | ||
Class E | 5 measurements at nominal value | ||
Class F | 10 measurements in a row for all values | ||
Class G | 5 measurements in a row for all values |
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