The best 3/8 threaded insert depends on the wood, insert length, and number of fasteners your project needs. The options below use a 3/8-16 internal thread and are designed for wood applications. Anwenk is best for a larger 25mm insert pack, OUSCHR offers 50 shorter 20mm inserts, and SVLING is suited to buyers who also need matching bolts.
| Product | Insert length | Pack details | Best for |
|---|---|---|---|
| Anwenk | 25mm | 40 inserts, hex spanner | Furniture projects needing a larger insert quantity |
| kvohlum | 25mm | 15 inserts, hex spanner | Smaller projects |
| OUSCHR | 20mm | 50 inserts, hex spanner | Buyers seeking a shorter insert in a bulk pack |
| Twidec | 25mm | 17-piece kit, hex wrench and drill bit | Repair work with included tools |
| SVLING | 25mm | 9 insert-and-bolt sets | Projects that need matching bolts |
Anwenk 40-Piece 25mm Wood Inserts
This pack contains 40 carbon-steel inserts with a 3/8-16 internal thread and a 25mm length. The listed external diameter is 15.35mm. A hex spanner is included, and the inserts have an internal hex drive described as non-slip and burr-free.
Best for: Furniture makers or repair projects that need multiple 25mm inserts for softwood, plywood, or composition board. It was selected for its comparatively large pack and clearly stated dimensions.
Consider: The 25mm body length may not suit every thickness of wood. Check the available material depth and the specified external diameter before drilling.
kvohlum 15-Piece 25mm Inserts
These 3/8-16 inserts measure 25mm long, with a listed external diameter of 15.2mm. They are made from zinc-plated carbon steel and come in a 15-piece pack with a hex spanner. The product description cites hardness, wear resistance, and corrosion resistance as material properties.
Best for: Smaller furniture or woodworking jobs where 15 inserts are enough and a 25mm insert is appropriate. The stated dimensions make it easier to compare this option with other 25mm products.
Consider: This pack has fewer inserts than the Anwenk and OUSCHR options, so it may be less convenient for a larger project.
OUSCHR 50-Piece 20mm Inserts
This set includes 50 inserts with 3/8-16 internal threads and a 20mm body length, plus a hex spanner. The listed head diameter is 16.6mm, body diameter is 11.9mm, and thread diameter is 15.1mm. Its external protrusions are described as biting into wood to help resist turning or pulling out.
Best for: Buyers who need a large quantity or prefer a shorter insert than the 25mm options. The product is described for use in pre-drilled holes in furniture and wooden products.
Consider: The listing advises drilling a correctly sized hole and notes that harder wood may require enlarging the hole. Follow the product’s installation guidance rather than forcing the insert.
Twidec 17-Piece Insert Kit
This kit is identified as 3/8-16 by 25mm and includes a hex wrench and drill bit. The carbon-steel inserts are described as high-hardness, wear-resistant, smooth, and burr-free. The product information mentions repairs to filing cabinets, chair legs, headboards, and footboards.
Best for: A repair or furniture project where having a drill bit and installation wrench in the kit is useful. Its stated furniture repair examples help distinguish it from packs that list inserts and a spanner only.
Consider: The supplied feature information does not state the drill bit’s size. Confirm that the hole size is appropriate for the insert and wood before installation.
SVLING Insert And Bolt Set
This set contains nine 3/8-16 x 25mm inserts, matching 3/8-16 x 1-1/4-inch flat-head bolts, and two hex wrenches. The inserts are galvanized carbon steel; the bolts are 304 stainless steel with a black zinc-plated surface. The listing describes the inserts for hardwood, softwood, and solid wood.
Best for: Projects that need both a wood insert and a matching 3/8-16 bolt. Choose this set if buying the fasteners together is more useful than receiving a larger quantity of inserts alone.
Consider: It contains nine sets, fewer inserts than the 40- and 50-piece options. Check that the flat-head bolt style suits the planned assembly.
Buying Guide: Choosing a 3/8-16 Insert
What does 3/8-16 mean?
For these products, 3/8-16 identifies the insert’s internal thread size: a 3/8-inch nominal thread with 16 threads per inch. Match this specification to the bolt or screw that will engage the insert. Do not assume that an insert with a different internal thread will fit just because its outer body looks similar.
Should you choose a 20mm or 25mm insert?
Compare insert length with the usable depth of the wood. The listed products include both 20mm and 25mm bodies. A longer insert is not automatically the right choice if the material is too thin or the hole cannot safely accommodate its length. Also compare external diameter, because the products list values around 15mm and may require different hole preparation.
How many inserts and tools do you need?
Choose pack size based on the number of attachment points and whether spare inserts are useful. The listed quantities range from nine insert-and-bolt sets to 50 inserts. Some options include a hex spanner or wrench, while the Twidec kit also lists a drill bit. Check the included-tool details and dimensions before starting work.
What should you check before installation?
Use the manufacturer’s hole-preparation instructions and keep the insert aligned as it is driven into the wood. The OUSCHR listing specifically calls for a well-sized pre-drilled hole and says harder wood may need a larger hole. Avoid forcing an insert into an undersized hole, which can make installation difficult or damage the surrounding material.
Frequently Asked Questions
Can a 3/8-16 insert accept any 3/8-inch bolt?
No. Match the bolt’s thread specification as well as its diameter. These inserts are listed with 3/8-16 internal threads, so choose a compatible 3/8-16 fastener.
Are these inserts intended for wood?
Yes. The products are described for wooden furniture and wood products, with some listings naming softwood, hardwood, plywood, or composition board.
Do all five options include a wrench?
The supplied product details list a hex spanner or wrench for each option. The Twidec kit also lists a drill bit.
Which option includes matching bolts?
The SVLING product is the listed insert-and-bolt set. Its package description includes nine inserts and nine corresponding 3/8-16 bolts.