Don't just tighten fasteners — prove they're still at spec. The INSIZE quality inspection torque wrench is built to verify the torque already on an installed fastener, not to set it. Retighten the bolt, watch the digital readout, and the wrench captures the exact torque at which it breaks loose — a fast, repeatable way to audit assembly torque on the production line or in the field.
A torque verification wrench for checking installed fasteners
The INSIZE IST-4W Series is designed specifically for inspection and quality control. Available from CRB Supply in four capacities from 6 to 340 N·m, it pairs digital torque measurement with peak and track modes, programmable pass/fail tolerance limits, and onboard memory — for precision assembly inspection, manufacturing QC, maintenance, and torque auditing.
Available models
| Model |
Torque Range |
Drive Size |
Accuracy CW |
Accuracy CCW |
Resolution |
| IST-4W30A |
6–30 N·m |
1/4" |
±2% |
±3% |
0.01 N·m |
| IST-4W135A |
27–135 N·m |
3/8" |
±2% |
±3% |
0.1 N·m |
| IST-4W200A |
40–200 N·m |
1/2" |
±2% |
±3% |
0.1 N·m |
| IST-4W340A |
68–340 N·m |
1/2" |
±2% |
±3% |
0.1 N·m |
Designed for torque inspection, not just tightening
The IST-4W Series is designed for applications where the goal is to verify torque on an existing fastener, rather than simply apply a predetermined tightening torque.
In manual detection mode, the operator retightens an existing bolt while monitoring the digital torque measurement. When the fastener begins to loosen, the wrench detects the corresponding torque value, providing an inspection measurement of the installed fastener.
This makes the IST-4W quality inspection torque wrench useful for:
Fastener torque verification
Assembly inspection
Production quality control
Torque auditing
Maintenance inspection
Installed-bolt verification
Manufacturing quality assurance
Digital torque measurement
The IST-4W provides a digital readout and supports both peak and track measurement modes. Clockwise and counter-clockwise operation allows the wrench to be used across a variety of inspection and assembly applications.
Available torque units include:
Pass/fail inspection
The IST-4W incorporates upper and lower torque tolerance limits for inspection applications. When tolerance limits are configured, the wrench provides audible and visual indications to help operators quickly determine whether a measured torque value falls within the specified range.
This is particularly useful in production environments where torque verification is performed repeatedly across multiple assemblies.
Measurement memory
The IST-4W Series can store up to 50 measurement results in its internal memory, giving operators a convenient way to retain recent inspection measurements without recording every result manually as it is taken.
Fixed ratchet head
The IST-4W Series uses a fixed ratchet head, with drive sizes selected according to the torque capacity of each model:
IST-4W30A: 1/4" drive
IST-4W135A: 3/8" drive
IST-4W200A: 1/2" drive
IST-4W340A: 1/2" drive
The ratcheting head provides convenient operation when accessing fasteners in assembly and inspection environments.
Accuracy & resolution
All four models provide ±2% clockwise and ±3% counter-clockwise accuracy. Resolution is 0.01 N·m on the IST-4W30A and 0.1 N·m on the IST-4W135A, IST-4W200A, and IST-4W340A.
Technical specifications
| Specification |
IST-4W Series |
| Product Type |
Quality Inspection Digital Torque Wrench |
| Primary Use |
Torque verification / inspection of installed fasteners |
| Clockwise Accuracy |
±2% |
| Counter-Clockwise Accuracy |
±3% |
| Resolution |
0.01 N·m (IST-4W30A); 0.1 N·m (IST-4W135A / 200A / 340A) |
| Measurement Modes |
Peak & Track |
| Operation |
Clockwise & Counter-Clockwise |
| Pass/Fail Limits |
Programmable upper & lower tolerances |
| Warning System |
Audible & visual indication |
| Memory |
Up to 50 measurement results |
| Head Type |
Fixed ratchet head |
| Drive Sizes |
1/4", 3/8", 1/2" (by model) |
| Torque Units |
N·m, in·lb, ft·lb, kg·cm |
| Available Range |
6–340 N·m, depending on model |
Where this quality inspection torque wrench is used
The INSIZE IST-4W is well suited for:
Production quality control
Assembly line torque audits
Installed-fastener verification
Manufacturing quality assurance
Maintenance and service inspection
Incoming and in-process inspection
Engineering and R&D testing
Technical documentation
For complete manufacturer specifications and operating information, refer to the official INSIZE documentation:
View the INSIZE IST-4W Series Technical Documentation
Need help selecting the right torque wrench?
The right model depends on the torque value you need to verify and the drive size your fasteners require. Contact CRB Supply before ordering and we'll help you match the correct INSIZE IST-4W configuration to your inspection application.
