For an automotive replacement, choose an indented hex head SEMS body bolt that matches the thread, length, washer, and vehicle hardware reference. The 5/16″-18 x 7/8″ options are best for buyers replacing GM-style body bolts; the 3/8″-16 option is for a different size and reference. A separate galvanized 1/2″ x 6″ bolt is intended for heavy-duty general fastening, not a direct substitute for an indented automotive body bolt.
| Product | Best For | Key Detail |
|---|---|---|
| 50-piece 5/16″-18 x 7/8″ SEMS bolts | Bulk GM-style replacements | References GM 12337916 and 3846202 |
| Rexka 10-piece body bolts | Smaller replacement set | 3/4″ washer; 1/2″ hex |
| 25-piece 5/16″-18 x 1 3/16″ bolts | Longer body bolt needs | 1/2″ hex; 7/8″ washer |
| 3/8″-16 x 1″ indented bolts | GM 3986997 replacement needs | Different thread size |
| 30-piece galvanized hex bolts | Outdoor heavy-duty fastening | 1/2″ x 6″; not an automotive SEMS match |
50-Piece 5/16″-18 x 7/8″ SEMS Bolts
This set is best for buyers who need multiple 5/16″-18 x 7/8″ replacement bolts for GM-related body or trim applications. The listing names GM 12337916 and 3846202 and describes the bolts as meeting OE standards. It also identifies steel construction and presents the kit as replacement hardware for missing, damaged, or failed original bolts.
Choose this option when the quantity and listed dimensions suit the repair. Its stated GM references make it easier to compare against existing hardware or a parts list. Confirm the application before ordering: the listing does not provide a complete vehicle fitment chart, and a 50-piece set may be more than a small repair requires.
Rexka 10-Piece GM Body Bolt Set
This is best for buyers seeking a smaller set of 5/16″-18 x 7/8″ GM-style body bolts. The listing specifies a 3/4-inch washer outside diameter, a 1/2-inch hex size, and phosphate finish. It identifies GM 12337916 and 3846202 as replacement references and mentions uses involving body, trim, and other vehicle areas.
Compared with the 50-piece option, this set has fewer pieces and more explicitly stated washer and hex measurements. Choose it if those dimensions and the GM references match the fastener being replaced. Avoid assuming that a listed general application guarantees fit on every Chevrolet or GMC model; verify the original bolt specifications.
25-Piece 5/16″-18 x 1 3/16″ Body Bolts
This option is best for a repair that specifically calls for a longer 5/16″-18 body bolt. The listing gives a 1 3/16-inch length, 1/2-inch hex, and 7/8-inch washer. Those measurements distinguish it from the 7/8-inch-long bolts above, despite sharing the same nominal thread size.
Choose this set when the installed bolt or repair specification confirms the longer length and washer size. The supplied product details do not state a vehicle reference, material, finish, or broader fitment information. Do not select it based on thread diameter alone; overall length and washer dimensions can affect fit and clamping.
3/8″-16 x 1″ Indented Hex Body Bolts
This product is best for buyers whose replacement specification calls for 3/8″-16 x 1″ hardware and references GM 3986997. The listing describes it as an OE-standard replacement made from steel and intended for replacing original hardware that is missing or damaged.
It was selected because it is explicitly an indented hex head SEMS body bolt, but it is not interchangeable with the 5/16″-18 options simply because the head style is similar. Confirm the 3/8″-16 thread, one-inch length, and GM reference before purchase. The provided details do not specify washer dimensions or a quantity.
30-Piece 1/2″ x 6″ Galvanized Hex Bolts
This is best for outdoor construction or heavy-duty fastening where a long, corrosion-resistant galvanized bolt is needed. The listing describes hot-dipped galvanized steel, coarse threads, and uses such as decks, fences, structural framing, and industrial maintenance.
This product is included as a general hex bolt comparison, not as a direct indented body bolt replacement. Its 1/2″ x 6″ dimensions differ substantially from the automotive SEMS options, and the feature list does not identify an indented head or attached washer. Avoid it for a body-bolt repair unless the project specification calls for these exact dimensions and construction.
Buying Guide: How to Choose an Indented Hex Head Bolt
Which dimensions should you match?
Check thread diameter, threads per inch, length, hex size, and washer diameter. For example, 5/16″-18 x 7/8″ is different from 5/16″-18 x 1 3/16″: the thread is the same, but the second bolt is longer. Compare the measurements with the removed fastener or a reliable parts specification.
Does the vehicle reference match?
Use listed GM reference numbers as comparison points, not as proof of universal fit. The 5/16″-18 products cite GM 12337916 and 3846202, while the 3/8″-16 product cites GM 3986997. Confirm the correct reference for the repair and check whether the intended position requires a particular washer or finish.
How many bolts do you need?
Choose quantity based on the repair and whether you want spares. A 10-piece set may suit a limited replacement job, while a 25- or 50-piece set can make sense when several fasteners are needed. Quantity alone does not establish compatibility, so confirm dimensions first.
When does finish matter?
Finish and material can matter in exposed or demanding environments, but the supplied product information varies. One automotive listing specifies phosphate finish, and others describe steel or OE-style replacement intent. The galvanized general-purpose bolts are described for outdoor and marine environments, but their size and head details make them a different category from automotive indented SEMS bolts.
Frequently Asked Questions
What is an indented hex head SEMS body bolt?
It is a hex-head body fastener sold as a SEMS-style bolt. Check the individual listing for washer details, since the supplied specifications do not describe every product’s washer construction.
Are 5/16″-18 and 3/8″-16 bolts interchangeable?
No. They have different nominal diameters and thread specifications. Use the size specified for the application.
Can I replace a 7/8-inch bolt with a 1 3/16-inch bolt?
Not automatically. The longer bolt may not fit the available space or match the intended clamping setup. Verify the required length before ordering.
Which option is best for GM 12337916 or 3846202?
The 50-piece and Rexka listings both name those GM references. Compare their quantities and stated dimensions with the original hardware before choosing.
Is the galvanized 1/2″ x 6″ bolt a body-bolt substitute?
Not based on the provided details. It is a long general-purpose hex bolt, not a listed indented automotive SEMS body bolt.