Shear Plates, Dapping Tools, and Spike Grids

Shear Plates

shear-plate-dscn0127-webAvailable in 3 sizes, shear plates are round, malleable iron discs that are designed to sit flush in precut grooves. Primarily intended for wood-to-steel connections, they can also be used in wood-to-wood connections. They allow for greater load-carrying capacity in shear than can be achieved by a bolt alone. Shear plates effectively increase the strength of joints in timber construction and reduce the number of bolts required.

Shear Plate Dimensions

Outside Diameter Depth Bolt Diameter Lumber Minimum Dimension Weight (lbs.) Per 100 Pieces Part Numbers
Plate in One Face Plate In Both Faces Plain Galvanized
258 .42 34 158 x 358 158 x 358 31 12346 12347
4 .62 34 158 x 512 134 x 512 89 12404 12405
4 .62 78 158 x 512 134 x 512 89 12406 12407

Dimensions per ASTM D5933

Dapping tools for shear plates

pb-dapping-tool-575The dapping tool for shear plates creates special grooves (aka daps) in timber and are required for proper installation of shear plates. Dapping tools can be used with either a drill press or a heavy duty ¾” drill.

View this video to see a dapping tool cutting grooves in timbers for the shear plates to be inserted into.

Tool Number Shear Plate Size Drilled Hole Size Dapping Tool Part Number Replacement Blade Part Number Replacement Pilot Part Number
303 / TSPT67 258 1316 18631 18636 18640
304 / TSPT102 4 1316 18634 18638 18640
304S / TSPT102S 4 1516 18633 18638 18641
Note: Tool 304 is required for 4" shear plates that are being used with 3/4" diameter bolts, while tool 304S is required for 4" shear plates that are being used with 7/8" diameter bolts.

Spike Grids

flat-spike-gridSpike grid timber connectors are engineered to enhance joint strength and rigidity while at the same time simplifying assembly procedures. Timber structures in which spike grid connectors are utilized include decks, pole frame buildings, pilings, wharves, and bridges or trestles. They are also used to advantage in the construction of pole-supported “building platforms” for conventional building of homes, resort buildings and other structures situated on hillsides as well as over or near water. Flat spike grids are used between sawn timbers, while single curved spike grids are used between round piles or poles and sawn members. Spike grids are manufactured from malleable iron in accordance with ASTM A47 grade 32510.

Type Part Number Finish Size Depth Bolt Hole Dia. Bolt Dia. Max Lumber Min. Dimensions
Grid in One Face Grid in Both Face
Flat 18687 Plain 4-1/8" x 4-1/8" 1" 1.06" 1" 1-5/8" x 5-1/2" 2-5/8" x 5-1/2"
18688 Galv
Single Curve 18681 Plain 4-1/8" x 4-1/8" 1.38" 1.06" 1" 1-5/8" x 5-1/2" --
18682 Galv