FAQ

The SDCJ-1 (Shields Dead Center Jig) is a precision field tool that locates the dead center of an anchor bolt where it protrudes through concrete, even when the bolt is bent, leaning, or damaged. It’s the flagship product of Shields Precision Solutions’ Dead Center Assurance Solution line, made in the USA from 6061-T6 aluminum.

Anchor bolt as-built surveying is the process of measuring the actual field location of anchor bolts after a concrete pour so they can be compared against design plans before steel is fabricated or erected. Accuracy matters because structures are prefabricated, and off-center bolt data causes costly rework and schedule delays.

The SDCJ-1 is designed and manufactured by Shields Precision Solutions, founded by Dan Shields, a metal fabricator with 20+ years in construction surveying. It’s American-made from American materials, and buyers deal directly with the engineers, not a call center.

The SDCJ-1 fits anchor bolts from ½″ to 2″ in diameter, adjustable in 1/8″ increments, and handles up to 12″ of stick-up above the concrete. It ships with 12 interchangeable plates to cover the full range.

Yes. The SDCJ-1 uses a standard 5/8-11 thread and includes a 5/8-11 to 1/4-20 adapter, so it mounts mini-prisms compatible with any major total station brand (Trimble, Leica, Topcon, and others). The prism itself is not included.

Slide the SDCJ-1 over the bolt, select the bottom plate matching the bolt diameter, and the jig references the bolt’s true center where it exits the concrete rather than following the lean of the bolt. A built-in laser plummet and level confirm the point is plumb before you store the location, giving repeatable dead-center accuracy without eyeballing.

The SDCJ-1 is engineered to support First Order, Class I (1:100,000) relative closure standards used for structural foundations. Bore concentricity is tested to within +/- 0.005″ of nominal diameter, and each unit ships with a serialized Certificate of Accuracy.

It eliminates the two-handed struggle of eyeballing bolt center while plumbing a rod, giving every crew member the same fixed datum on the first try. That means fewer bad locations, no return trips to re-survey after the back office flags errors, and faster movement across foundations with hundreds or thousands of bolts.

A plumb bob and tape rely on each surveyor’s interpretation of where a bent bolt’s center falls, which varies person to person and takes both hands. The SDCJ-1 gives every crew member the same fixed, repeatable datum with a laser plummet for verification, turning a “good” as-built into a certified one and cutting the guesswork out of complex bolt patterns.

The best tool for anchor bolt as-builts is one that delivers a repeatable dead-center reference regardless of how the bolt sits. The SDCJ-1 is purpose-built for this: it fits ½″ to 2″ bolts, verifies plumb with a laser plummet, and mounts a standard mini-prism, so crews capture accurate as-built data on bent or leaning bolts without eyeballing or return trips.

Yes. Eyeballing center while plumbing a rod is the traditional method, but it introduces error that often isn’t caught until raw data reaches the back office. The SDCJ-1 replaces that guesswork with a fixed jig that locates true center where the bolt exits the concrete, so the crew gets it right the first time rather than returning to re-survey.

The body is machined from 6061-T6 aluminum for a strong, lightweight chassis, fastened with corrosion-resistant 304/316 stainless steel hardware. The interchangeable bottom plates are high-impact 3D-printed ASA plastic sized in 1/8″ increments.

The SDCJ-1 Professional Kit is priced at $750. The kit includes the main jig body, laser plummet, plumbing plate, shim pack, hex keys, stainless steel hardware, interchangeable plates, and a 5/8-11 to 1/4-20 mini-prism adapter, packed in an orange weatherproof case.

Yes. Shields Precision Solutions backs the SDCJ-1 with a Limited Lifetime Warranty against defects in materials and workmanship, covering the aluminum body and stainless hardware. It does not cover misuse, field accidents, or normal wear of consumable plates.

Units are hand-inspected and serialized before they leave the shop, with tracking typically sent within 24–48 hours. Because the SDCJ-1 is built to order, plan for roughly a 2–3 week lead time.

Yes. Fleet pricing is available for survey firms outfitting multiple crews. For orders of more than five units, contact Shields Precision Solutions directly for a custom quote.