Obstacle Insert Sets


Blackhawk by Proto, a sub-brand of  Proto industrial tools, is proud to announce a new concept in wrench design: Obstacle Insert Sets. Each set is built around the familiar reverse-ratcheting S-shaped wrench – a proven design for helping technicians work around obstructions in tight spaces – but includes adaptors that let the technician turn several fastener sizes with just one wrench body. Think of it as the box-end equivalent of a ratchet-and-socket socket set.
Each set includes one 8-inch long wrench body, six flank adaptors, and an equal number of box heads. Each flank adaptor is designed to slip into one of the wrench openings, while each box head attaches to its corresponding flank adaptor. This system lets the user quickly change the size of the wrench opening. Sets are available in Fractional (3/8 in. to 7/8 in.) and Metric (10 mm to 22 mm) versions.
Blackhawk designed these sets with considerable input and feedback from working technicians. One of their concerns was torque capacity. In response, the wrench body has been engineered so that the interchangeable heads do not reduce torque capacity: once in place, the adaptor transfers torque forces to the wrench body, minimizing stress on the adaptor.
Technicians also asked that is be easy for them to change heads without having to move around – an important consideration where there is limited maneuvering room, such as under a car. While the adaptors are held securely in place with a locking ring, they can be quickly disengaged via a thumb release.
Toughness and ease of use are combined with adaptability and cost savings. In the past, technicians had to buy a separate wrench for each fastener size. Now, they can get a single S-shaped wrench that has the ability to turn six different fasteners, all in a kit that weights just 2.8 lbs and is easy to carry from place to place. In addition, sets offer significant a cost savings over buying separate wrenches.
Obstacle Insert Sets have the same advantages as any S-shaped wrench when working around obstructions in an engine compartment, since they let the technician reach fasteners that a straight wrench can't. Even where a straight wrench could be used, the S-shaped wrench often allows a greater arc swing. By adding the flexibility of different head sizes, Obstacle Insert Sets take this useful design and make it more useful than ever.


  • turn several fastener sizes with just one wrench body
  • work around obstructions in tight spaces

2 User Reviews

Add your review:
Hi Anonymous, This product was posted in 2011. Hope this helps! --NED
These sets are not new at all. I know because I bought them quite a few years ago. "A new concept in wrench design"? No.