ASME B107.300-2021 pdf download

ASME B107.300-2021 pdf download.Hand Torque Tools and Torque Testers.
5.1.4 Type III — Limiting
(a) Operation. Limiting torque instruments shall operate by releasing the drive tang at the preselected torque value followed by automatic reset. The release and reset sequence shall occur a minimum of two times in one full revolution of the drive. The reset action should not cause a reverse torque (backlash), which might loosen the fastener being tightened.
(b) Type ill, ClassA —ScrewdriverGrip. The instrument shall be in a screwdriver configuration. The full scale setting of Type III, Class A instruments shall not exceed 40 Ibf-in. (4.5 N.m).
NOTE: This limitation is for safety reasons.
(1) Type 111, Class A, Style 1 — Graduated. A graduated scale with increments appropriately numbered shall be located on the instrument and positioned to permit convenient reading. Selection of the torque value shall be made by manual means not requiring a separate tool or implement. Provision shall be made to accurately indicate the selected torque value on the graduated scale. The adjustment means shall be adequately protected against accidental change by an appropriate device or lock not requiring a separate tool or implement.
The instrument may be similar to that shown in Figures 5.1.4-1 and 5.1.4-2.
(2) Type III, Class A, Style 2 — Nongradua ted. The torque instrument shall not be graduated or equipped with a means for graduated adjustment. A separate tool or implement shall be required to engage the adjustment provision of the instrument in order to select the torque value. Means shall be provided to protect the torque setting from accidental changes. The instrument may be similar to that shown in Figures 5.1.4-3 and 5.1.4-4.
(c) Type III, Class A, Styles 1 and 2, Design A — External Square Drive. A 1/4-in. (6.3-mm) square drive tang without auxiliary operational features shall be provided. The drive shall comply with the requirements of para. 5.7.1.
(d) Type III, Class A, Styles 1 and 2, Design B — Internal Hex Drive. A 1/4-in. (6.3-mm) hexagon socket drive integral with the torque instrument shall be provided. The drive shall comply with the requirements of para. 5.7.3.
(e) Type Ill, Class B — T-Handle Grip. The instrument shall be in a T-handle configuration and may be similar to that shown in Figure 5.1.4-5. The instrument shall not be graduated nor equipped with a means for graduated adjustment. A separate tool or implement shall be required to engage the adjustment provision of the instrument in order to select the controlling torque value.
Means shall be provided to protect the torque setting from accidental changes. The full-scale setting shall not exceed 150 lbf-in. (16.9 N.m). The drive shall comply with the requirements of para. 5.7.1.
(1) Type ill, Class B, Style 1 — Nonratcheting. A square drive tang without auxiliary operational features shall be provided.
(2) Type Ill, Class B, Style 2 — Ratcheting. A square drive tang with an integral ratcheting mechanism shall be provided. The ratchet shall be non reversible and provide driving engagement in the clockwise direction. The ratchet shall index a minimum of eight times in one full revolution of the drive.
(/3 Calibration. Type III instruments shall be calibrated in a clockwise direction.
5.1.5 Type IV Break-Over. The drive tang of the torque instrument shall stay stationary while the body of the instrument shall pivot about a holding pin when torque is reached. The minimum amount of rotation shall be 10 deg. The torque instrument may or may not reset when force is released on the handle (see Figure 5.1.5-1).
5.2 Design — Category 28 ELectronic
The torque instrument shall be capable of electronically indicating the torque applied clockwise and counterclockwise using a transducer and digital display. The torque value readout shall be visible at a viewing angle up to 45 deg from normal. It shall have an integral power supply capable of meeting the requirements specified in para. 5.15.
Type I shall indicate torque only.
Type II shall indicate torque and angle either alternatively or simultaneously.
Type III shall indicate torque and have the grip and drive lie on the same axis of rotation to allow the instrument to be used like a screwdriver. Instruments shall be limited to a capacity of 100 lbf-in. (11.3 N.m), and those with capacities over 40 lbf-in. (4.5 N.m) shall be equipped with auxiliary driving means, such as a T-handle.