299108-1 · Cap & socket
Look for the 1/4-inch cap version of the cap-and-socket assembly.
Identify Sea-Dog Boat-Cover Canvas Snaps by MPN and Screw Size
A worn snap on a boat cover can involve different parts on the canvas and the mounting surface. Sea-Dog's 299-series includes cap-and-socket sets, screw-mounted studs, two-screw turnbuckles and add-on extensions. Use the fastener type and exact screw or cap measurements to identify a suitable part rather than choosing by appearance alone.
Identify the part of the snap that needs replacement
Fabric-side cap and socket
299108-1 uses a 1/4-inch cap; 299109-1 uses 5/16 inch. Each is a cap-and-socket pairing rather than a screw-mounted stud.
Mounting-point studs
299111-1 is #8 × 3/8 inch; 299112-1 is #8 × 5/8 inch; 299113-1 is #10 × 5/8 inch. Check both gauge and length.
Special fasteners
299116-1 has a two-screw turnbuckle base. Black Add-A-Snap 299201B-1 and 299202B-1 have different extension dimensions.
Working on the canvas
299190-1 is an installation tool supplied with three removable dies. It is not intended for heavy-duty stainless canvas snaps.
Cover side
Cap + socket
299108-1 or 299109-1
Mounting point
Screw-on stud
299111-1, 299112-1 or 299113-1
Canvas snap part-number comparison
Part numbers identify different fastening designs. The reference quantities below describe Sea-Dog's catalog sets, not a verified quantity for every store product listing.
| Sea-Dog MPN | Component | Key size or description | Manufacturer reference |
|---|---|---|---|
| 299108-1 | Cap & socket | 1/4-in cap; socket | 6 caps and 6 sockets per manufacturer set |
| 299109-1 | Cap & socket | 5/16-in cap; socket | 6 caps and 6 sockets per manufacturer set |
| 299111-1 | Screw-on stud | #8 sheet-metal screw × 3/8 in | 6 studs per manufacturer set |
| 299112-1 | Screw-on stud | #8 sheet-metal screw × 5/8 in | 6 studs per manufacturer set |
| 299113-1 | Screw-on stud | #10 sheet-metal screw × 5/8 in | 6 studs per manufacturer set |
| 299116-1 | Snap turnbuckle | Two-screw mounting base | 2 per manufacturer set |
| 299190-1 | Installation tool | Die wrench and 3 removable dies | Aluminum/steel; not for heavy-duty stainless snaps |
| 299201B-1 | Add-A-Snap extension | Black; drawing A 1-1/2 in; C 11/16 in | Drawing B 1 in; nylon/nickel-plated brass |
| 299202B-1 | Add-A-Snap extension | Black; drawing A 2-1/2 in; C 1-1/2 in | Drawing B 1 in; nylon/nickel-plated brass |
Why the cap and stud numbers differ
Black 299201B-1 has manufacturer drawing A/B/C dimensions of 1-1/2, 1 and 11/16 inches. Black 299202B-1 has A/B/C of 2-1/2, 1 and 1-1/2 inches. These letters refer to the manufacturer's own drawing labels, not interchangeable hole-cutout dimensions. Check the original fastener arrangement.
The 299190-1 setting tool is intended for compatible canvas snaps and is not recommended by Sea-Dog for heavy-duty stainless canvas fasteners.
How to check an old snap
- Check whether the missing or damaged piece is the cap-and-socket on the cover or a screw-mounted stud on the boat.
- Compare the cap height if replacing 299108-1 or 299109-1. Check both screw gauge and length for stud replacements.
- For black Add-A-Snap extenders, compare the manufacturer's A, B and C drawing measurements and the cover attachment before ordering.
- Review the current listing for the actual sales unit and contents. A manufacturer's catalog set quantity is not necessarily a store listing quantity.
Find the exact Sea-Dog canvas hardware
These cards link each part number to its matching listing. Open the item to review current condition, availability and package details.
299109-1 · Cap & socket
Compare the 5/16-inch cap with 299108-1's 1/4-inch part before replacing.
299111-1 · Screw-on stud
Identify by #8 screw gauge and 3/8-inch screw length, not just the snap head.
299112-1 · Screw-on stud
This has the same #8 gauge as 299111-1 but a 5/8-inch screw.
299113-1 · Screw-on stud
Distinguish the larger #10 screw from the #8 versions even though both can be 5/8 inch long.
299116-1 · Snap turnbuckle
A two-screw-base turnbuckle, not a standard push-on snap cap or threaded stud.
299190-1 · Installation tool
This is the installation tool, not a fastener; check the snap type before use.
299201B-1 · Add-A-Snap extension
Shorter Add-A-Snap style; manufacturer drawing A is 1-1/2 inches.
299202B-1 · Add-A-Snap extension
Longer Add-A-Snap style, A 2-1/2 inches; not the same size as 299201B-1.
Related marine hardware identification
Identify Sea-Dog Bimini top fittings · Identify marine boat snaps and swivel hooks
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