Skip to content
Celebrating over 50 years of Trusted Marine Service
Over 50 years of Trusted Marine Service

Fasteners & Mounting

Marine Hardware & Installation

Marine Fasteners, Mounting Hardware & Installation Supplies

Shop marine-grade screws, bolts, nuts, washers, brackets, backing plates, rivets, mounting pads, sealants, thread lockers, and anti-seize for secure hardware installations in saltwater environments.

Shop Fasteners & Mounting Stainless Screws Mounting Brackets
Install Check

Match metal grade, fastener size, thread type, backing support, bedding compound, and load direction before drilling into the boat.

Shop Backing Plates

Use marine-grade hardware and proper sealing practices. Confirm load ratings, material compatibility, corrosion risk, deck core protection, and manufacturer instructions before installation.

Quick ShopFitmentHardware TypesInstall NotesInspectionFAQDeck HardwareTools

Fitment

Choose the Right Metal, Size, and Support

Marine fasteners need to match the job. Consider stainless grade, length, diameter, head style, thread type, washer size, backing plate needs, and whether the hardware is loaded in pull, shear, or vibration.

316 Stainless 304 Stainless Threaded Rod

Corrosion

Saltwater Hardware Needs Material Discipline

316 stainless is commonly preferred for saltwater exposure, while 304 stainless may suit freshwater or less demanding areas. Isolate dissimilar metals where needed and use anti-seize on stainless threads to reduce galling.

If a fastener is structural or safety-critical, confirm the correct grade, torque, backing, and installation method.

SS

Stainless Fasteners

Screws, bolts, nuts, washers, threaded rod, lock nuts, and specialty head styles for marine repair and upgrades.

MNT

Mounting Hardware

Brackets, bases, pads, backing plates, antenna mounts, rod holder mounts, and accessory supports.

BED

Bedding & Bonding

Sealants, adhesives, thread lockers, anti-seize, and bedding compounds help hardware stay secure and watertight.

Install Notes

Seal Holes and Spread Loads

Fastener selection is only part of the job. Hardware installed through decks, cabins, rails, transoms, or cored panels needs the right pilot hole, sealant, backing, washer, and torque.

Pilot holesUse the correct drill size for the fastener, substrate, and thread engagement.
Bedding compoundSeal penetrations to keep water out of cores, cabins, lockers, and electronics areas.
Backing platesSpread loads for cleats, davits, ladders, rails, seats, and high-load deck hardware.
Thread careUse thread locker or anti-seize where appropriate, especially on stainless-to-stainless threads.

Inspection

Replace Corroded, Loose, or Mismatched Hardware

Check for rust streaks, loose brackets, elongated holes, cracked sealant, missing washers, galvanic corrosion, stripped threads, and water intrusion around mounted hardware.

Washers Nuts Adhesives

Projects

Good Hardware Makes Upgrades Last

Electronics, antennas, cleats, rod holders, seats, speakers, lights, ladders, hatches, and deck fittings all rely on correctly chosen mounting hardware.

For heavy or safety-related gear, do a dry fit, mark hole locations carefully, and confirm access to the backside before drilling.

FAQ

Marine Fastener Questions

Should I use 304 or 316 stainless fasteners on a boat?

316 stainless is usually preferred for saltwater and exposed marine use because it has stronger corrosion resistance. 304 stainless can be suitable for freshwater or less exposed applications.

Why do stainless fasteners seize or gall?

Stainless threads can gall when tightened under friction, especially stainless-on-stainless. Anti-seize, correct thread engagement, and careful tightening can help reduce the risk.

When do I need a backing plate?

Use backing plates when hardware carries significant load, such as cleats, rails, ladders, davits, seats, and deck fittings. Backing plates spread load and help prevent crushing or pull-through.

Should deck fasteners be sealed?

Yes. Holes through decks, cabins, and cored panels should be sealed with the correct marine bedding compound to help prevent leaks and core damage.

Ready for a Stronger Install?

Shop Marine Fasteners, Brackets, Backing Plates & Sealants

Search by fastener type, material, size, head style, mounting application, sealant need, bracket type, or installation project.

Shop Fasteners & Mounting Backing Plates Sealants

Filters

Lag Screw, 5/16 x 2"

Lag Screw, 5/16 x 2"

$60.59 - $60.59
$60.59
$60.59 - $60.59
$60.59
Item locally warehoused

A durable 5/16 x 2" lag screw for marine and general fastening needs, made from 18-8 stainless steel. Key Features Size: 5/16 x 2" Material: 18-8 ...

View full details
$60.59 - $60.59
$60.59
$60.59 - $60.59
$60.59
Carriage Bolt, 1/4"-20 x 2-1/2"

Carriage Bolt, 1/4"-20 x 2-1/2"

$49.99 - $49.99
$49.99
$49.99 - $49.99
$49.99
Item locally warehoused

A marine-grade carriage bolt designed for clean installation with a square neck that helps prevent rotation. This size is 1/4"-20 x 2-1/2" in 18-8 ...

View full details
$49.99 - $49.99
$49.99
$49.99 - $49.99
$49.99
Lag Screw, 5/16 x 1-1/2"

Lag Screw, 5/16 x 1-1/2"

$38.69 - $38.69
$38.69
$38.69 - $38.69
$38.69
Item locally warehoused

A durable stainless-steel lag screw sized 5/16 x 1-1/2" for fastening applications where corrosion resistance matters. Key Features Size: 5/16 x 1...

View full details
$38.69 - $38.69
$38.69
$38.69 - $38.69
$38.69
Lag Screw, 5/16 x 1"

Lag Screw, 5/16 x 1"

$38.29 - $38.29
$38.29
$38.29 - $38.29
$38.29
Item locally warehoused

Replace worn or missing fasteners with this 5/16" x 1" lag screw made from 18-8 stainless steel for reliable corrosion resistance in marine hardwar...

View full details
$38.29 - $38.29
$38.29
$38.29 - $38.29
$38.29
Cap Screw - Hex Head, 3/8"-16 x 6"

Cap Screw - Hex Head, 3/8"-16 x 6"

$56.69 - $56.69
$56.69
$56.69 - $56.69
$56.69
Item locally warehoused

Secure assemblies with this hex head cap screw sized 3/8"-16 x 6"—finished in 18-8 stainless steel for corrosion resistance in marine and outdoor e...

View full details
$56.69 - $56.69
$56.69
$56.69 - $56.69
$56.69
Cap Screw - Hex Head, 1/4-20 x 5/8"

Cap Screw - Hex Head, 1/4-20 x 5/8"

$68.59 - $68.59
$68.59
$68.59 - $68.59
$68.59
Item locally warehoused

Secure components with this 1/4-20 x 5/8" hex head cap screw made from 18-8 stainless steel—ideal for corrosion-resistant fastening on marine and o...

View full details
$68.59 - $68.59
$68.59
$68.59 - $68.59
$68.59
Cap Screw - Hex Head, 1/4-20 x 1/2"

Cap Screw - Hex Head, 1/4-20 x 1/2"

$79.01 - $79.01
$79.01
$79.01 - $79.01
$79.01
Item locally warehoused

A corrosion-resistant hex head cap screw for secure, threaded fastening—ideal for marine and other demanding environments where stainless hardware ...

View full details
$79.01 - $79.01
$79.01
$79.01 - $79.01
$79.01
Cap Screw - Hex Head, 1/4-20 x 3/4"

Cap Screw - Hex Head, 1/4-20 x 3/4"

$67.19 - $67.19
$67.19
$67.19 - $67.19
$67.19
Item locally warehoused

A durable hex head cap screw sized 1/4-20 x 3/4" for marine hardware and general fastening needs. Key Features Hex head cap screw for a secure wre...

View full details
$67.19 - $67.19
$67.19
$67.19 - $67.19
$67.19
Cap Screw - Hex Head, 3/8"-16 x 5"

Cap Screw - Hex Head, 3/8"-16 x 5"

$55.59 - $55.59
$55.59
$55.59 - $55.59
$55.59
Item locally warehoused

Keep hardware secure with a durable Seachoice hex head cap screw sized for 3/8"-16 threads and 5" length—an ideal choice for marine fastener replac...

View full details
$55.59 - $55.59
$55.59
$55.59 - $55.59
$55.59
Phillips Machine Screw - Flat Head, 8-32 x 1"

Phillips Machine Screw - Flat Head, 8-32 x 1"

$39.49 - $39.49
$39.49
$39.49 - $39.49
$39.49
Item locally warehoused

Replace or stock up on a Phillips machine screw for marine and general mounting applications with a flat head design and 8-32 x 1" size. Key Featur...

View full details
$39.49 - $39.49
$39.49
$39.49 - $39.49
$39.49
Phillips Tapping Screws - Oval Head, #14 x 1-1/2"

Phillips Tapping Screws - Oval Head, #14 x 1-1/2"

$62.99 - $62.99
$62.99
$62.99 - $62.99
$62.99
Item locally warehoused

Phillips tapping screws with an oval head for a secure fastening application. Sized #14 x 1-1/2" and made from 18-8 stainless steel for corrosion-r...

View full details
$62.99 - $62.99
$62.99
$62.99 - $62.99
$62.99
Cap Screw - Hex Head, 3/8"-16 x 4-1/2"

Cap Screw - Hex Head, 3/8"-16 x 4-1/2"

$40.79 - $40.79
$40.79
$40.79 - $40.79
$40.79
Item locally warehoused

A corrosion-resistant hex head cap screw sized for marine hardware installations where a strong, wrench-tightened fastener is needed. Key Features ...

View full details
$40.79 - $40.79
$40.79
$40.79 - $40.79
$40.79

Volvo Penta - Lock Washer - 861652

$39.50 - $39.50
$39.50
$39.50 - $39.50
$39.50
Only 1 left!

The Volvo Penta 861652 is a genuine OEM lock washer used in the cooling system assembly on select Volvo Penta KAD-series marine diesel engines. Thi...

View full details
$39.50 - $39.50
$39.50
$39.50 - $39.50
$39.50

Volvo Penta - Mounting Stud 103mm - 853982

$46.40 - $46.40
$46.40
$46.40 - $46.40
$46.40
Only 3 left!

The Volvo Penta 853982 is a genuine OEM threaded mounting stud used as a structural engine fastener on select Volvo Penta gasoline and diesel marin...

View full details
$46.40 - $46.40
$46.40
$46.40 - $46.40
$46.40

N-10 Inch-Series Bearing Locknut 1.967"-18 TPI - N0-10

$10.75 - $10.75
$10.75
$10.75 - $10.75
$10.75
8 in stock

The N0-10, also commonly written as N-10, is a standard inch-series bearing locknut used to secure rolling bearings, pulleys, gears, sleeves, and o...

View full details
$10.75 - $10.75
$10.75
$10.75 - $10.75
$10.75

Mercury MerCruiser #10-32 Well Nut - 11-42290

$3.28 - $3.28
$3.28
$3.28 - $3.28
$3.28
Only 4 left!

The Mercury MerCruiser Quicksilver 11-42290 is a genuine Mercury Marine OEM well nut used as diagram-specific expansion mounting hardware on select...

View full details
$3.28 - $3.28
$3.28
$3.28 - $3.28
$3.28

Mercury 4-Stroke Outboard Oil Drain Screw Washer - 12-803516

$9.85 - $9.85
$9.85
$9.85 - $9.85
$9.85
6 in stock

The Mercury MerCruiser Quicksilver 12-803516 is a genuine Mercury Marine OEM engine oil drain screw washer used on select small Mercury 4-stroke ou...

View full details
$9.85 - $9.85
$9.85
$9.85 - $9.85
$9.85

Mercury MerCruiser 1/4-28 Hex Nut - 11-8267139

$3.81 - $3.81
$3.81
$3.81 - $3.81
$3.81
6 in stock

The Mercury MerCruiser Quicksilver 11-8267139 is a genuine Mercury Marine OEM .250-28 hex nut used as diagram-specific fastening hardware across se...

View full details
$3.81 - $3.81
$3.81
$3.81 - $3.81
$3.81

Volvo Penta Lock Nut - 990990

$4.90 - $4.90
$4.90
$4.90 - $4.90
$4.90
6 in stock

The Volvo Penta 990990 is a genuine Volvo Penta OEM lock nut used as diagram-specific structural hardware on select Volvo Penta diesel engine, ster...

View full details
$4.90 - $4.90
$4.90
$4.90 - $4.90
$4.90

Mercury MerCruiser Anchor Pin Flat Washer - 12-85058

$6.14 - $6.14
$6.14
$6.14 - $6.14
$6.14
10 in stock

The Mercury MerCruiser Quicksilver 12-85058 is a genuine Mercury Marine OEM flat washer used in select MerCruiser sterndrive, transom, trim, and Me...

View full details
$6.14 - $6.14
$6.14
$6.14 - $6.14
$6.14

Mercury MerCruiser Flat Washer 2-Pack - 12-44164

$6.14 - $6.14
$6.14
$6.14 - $6.14
$6.14
Only 2 left!

The Mercury MerCruiser Quicksilver 12-44164 is a genuine Mercury Marine OEM flat washer used in select MerCruiser sterndrive, transom, and engine a...

View full details
$6.14 - $6.14
$6.14
$6.14 - $6.14
$6.14

Mercury MerCruiser Propeller Shaft Toothed Lockwasher - 13-423511

$4.41 - $4.41
$4.41
$4.41 - $4.41
$4.41
Only 2 left!

The Mercury MerCruiser Quicksilver 13-423511 is a genuine Mercury Marine OEM toothed lockwasher used in select Mercury, Mariner, and MerCruiser pro...

View full details
$4.41 - $4.41
$4.41
$4.41 - $4.41
$4.41

Mercury Mariner M8 Mounting Stud - 16-424632

$25.06 - $25.06
$25.06
$25.06 - $25.06
$25.06
Only 2 left!

The Mercury MerCruiser Quicksilver 16-424632 is a genuine Mercury Marine OEM metric mounting stud used as diagram-specific bracket and component ha...

View full details
$25.06 - $25.06
$25.06
$25.06 - $25.06
$25.06

Mercury MerCruiser Propeller Tab Washer 14-34817 | Bravo Two Sterndrive

$20.30 - $20.30
$20.30
$20.30 - $20.30
$20.30
Only 4 left!

Mercury MerCruiser Propeller Tab Washer — Part No. 14-34817 This is the genuine Mercury Marine OEM propeller tab washer for MerCruiser Bravo Two st...

View full details
$20.30 - $20.30
$20.30
$20.30 - $20.30
$20.30

Mercury MerCruiser Gimbal & Bell Housing Screw 10-34763 — Pack of 5

$11.69 - $11.69
$11.69
$11.69 - $11.69
$11.69
Only 5 left!

Mercury MerCruiser Gimbal & Bell Housing Screw — Part No. 10-34763 | Pack of 5 This listing is for a pack of 5 genuine Mercury Marine OEM screw...

View full details
$11.69 - $11.69
$11.69
$11.69 - $11.69
$11.69

Mercury Quicksilver Double-Wound Split Lock Washer 13-33734 | MerCruiser Flywheel & Engine Mount Hardware

$4.04 - $4.04
$4.04
$4.04 - $4.04
$4.04
Only 2 left!

Double-Wound Split Lock Washer for MerCruiser Flywheel & Engine Mount ApplicationsThe Mercury Quicksilver 13-33734 is an OEM heavy-duty double-...

View full details
$4.04 - $4.04
$4.04
$4.04 - $4.04
$4.04

Mercury MerCruiser Rear Engine Mount Washer – 12-32834

$10.64 - $10.64
$10.64
$10.64 - $10.64
$10.64
13 in stock

Mercury MerCruiser Rear Engine Mount Washer – 12-32834This OEM structural washer is used in the rear engine mount stack-up on MerCruiser sterndrive...

View full details
$10.64 - $10.64
$10.64
$10.64 - $10.64
$10.64

Mercury - Engine Mounting Screw - 10-8M2021918

$3.89 - $3.89
$3.89
$3.89 - $3.89
$3.89
Only 2 left!

The Mercury Quicksilver Engine Mounting Screw 10-8M2021918 is an OEM structural fastener used in select Mercury/MerCruiser engine mounting applicat...

View full details
$3.89 - $3.89
$3.89
$3.89 - $3.89
$3.89

Mercury MerCruiser Quicksilver Stainless Nut 1/4-20 814101

$3.84 - $3.84
$3.84
$3.84 - $3.84
$3.84
Only 5 left!

Mercury MerCruiser Quicksilver 11-814101 is a .250-20 stainless steel nut used across select Mercury, Mariner, and MerCruiser assemblies. Current M...

View full details
$3.84 - $3.84
$3.84
$3.84 - $3.84
$3.84

Mercury MerCruiser Quicksilver Bell Housing Washer 806241

$9.04 - $9.04
$9.04
$9.04 - $9.04
$9.04
Only 4 left!

Mercury MerCruiser Quicksilver 12-806241 is a bell housing washer used on select MerCruiser bell housing assemblies, including applications identif...

View full details
$9.04 - $9.04
$9.04
$9.04 - $9.04
$9.04

Mercury MerCruiser Black Oxide Screw 438-14 x 2.060 843917

$12.65 - $12.65
$12.65
$12.65 - $12.65
$12.65
Only 1 left!

Mercury MerCruiser 843917 is a genuine OEM black oxide screw sized .438-14 x 2.060. Current Mercury dealer references show 843917 superseded to 8M0...

View full details
$12.65 - $12.65
$12.65
$12.65 - $12.65
$12.65

Mercury Outboard Latch Lever Screw M6 x 30 40019130

$2.74 - $2.74
$2.74
$2.74 - $2.74
$2.74
Only 1 left!

Mercury Quicksilver 40019130, commonly listed as 10-40019130, is a genuine OEM M6 x 30 screw. Current Mercury parts sources identify it simply as S...

View full details
$2.74 - $2.74
$2.74
$2.74 - $2.74
$2.74

Mercury MerCruiser Screw M6 x 14 4000327

$4.45 - $4.45
$4.45
$4.45 - $4.45
$4.45
6 in stock

Mercury MerCruiser Quicksilver 4000327, commonly listed as 10-4000327, is a genuine OEM screw identified by current Mercury dealer sources as SCREW...

View full details
$4.45 - $4.45
$4.45
$4.45 - $4.45
$4.45

Quicksilver Screw 29081 | 7/16-14 × 1-1/4 in. | Anodic Plate to Gear Housing | Mercury MerCruiser OEM

$7.41 - $7.41
$7.41
$7.41 - $7.41
$7.41
Only 5 left!

Quicksilver OEM Screw — Part No. 29081 / 10-29081 Part Number: 29081 Service Format: 10-29081 Supersedes: 57900 → 29081 (current) Brand: Quic...

View full details
$7.41 - $7.41
$7.41
$7.41 - $7.41
$7.41

ABA #12 Stainless Steel Hose Clamp 7/8" – 1-1/4" (ABA-13632)

$9.67 - $9.67
$9.67
$9.67 - $9.67
$9.67
160 in stock

The ABA #12 Stainless Steel Hose Clamp is a precision-engineered worm-drive clamp with a clamping range of 7/8" to 1-1/4" — purpose-built for deman...

View full details
$9.67 - $9.67
$9.67
$9.67 - $9.67
$9.67

MOB Mounting Bracket Model 403 – Black (MOB-MBRKT-M2B)

$13.28 - $13.28
$13.28
$13.28 - $13.28
$13.28
Only 5 left!

The MOB Mounting Bracket Model 403 in Black is a dedicated mounting solution for man overboard (MOB) safety equipment. Designed to provide a secure...

View full details
$13.28 - $13.28
$13.28
$13.28 - $13.28
$13.28

Volvo Penta Throttle Body Stud 3858964

$29.50 - $29.50
$29.50
$29.50 - $29.50
$29.50
Only 3 left!

Volvo Penta OEM Throttle Body Stud – Part No. 3858964 Part Number 3858964 Brand Volvo Penta Component Type Throttle Body Stud Syst...

View full details
$29.50 - $29.50
$29.50
$29.50 - $29.50
$29.50

Volvo Penta Hexagon Screw 191844 | DPH-D1 Marine Propulsion OEM

$18.60 - $18.60
$18.60
$18.60 - $18.60
$18.60
Only 1 left!

Volvo Penta 191844 – Hexagon Screw Part Number: 191844  |  Brand: Volvo Penta  |  Type: OEM Hexagon Screw  |  Supersedes: 3854685  |  Sold: Indivi...

View full details
$18.60 - $18.60
$18.60
$18.60 - $18.60
$18.60
Sold out

Mercury MerCruiser Keyed Washer 18323

$37.34 - $37.34
$37.34
$37.34 - $37.34
$37.34
Out of stock

Mercury MerCruiser Quicksilver 18323 is a genuine keyed tab washer used in selected Mercury and MerCruiser assemblies where a keyed locking washer ...

View full details
$37.34 - $37.34
$37.34
$37.34 - $37.34
$37.34
Sold out

MerCruiser Washer – 895146

$5.10 - $5.10
$5.10
$5.10
$5.10 - $5.10
$5.10
18 in stock

Genuine MerCruiser OEM Washer – Part No. 895146Keep your MerCruiser engine assembled to factory specification with the genuine MerCruiser OEM Washe...

View full details
$5.10 - $5.10
$5.10
$5.10
$5.10 - $5.10
$5.10

Volvo Penta Screw – 855605

$5.10 - $5.10
$5.10
$5.10 - $5.10
$5.10
Only 4 left!

Volvo Penta OEM Screw – 855605Genuine Volvo Penta OEM screw for Volvo Penta marine engine and sterndrive applications. Used to secure engine covers...

View full details
$5.10 - $5.10
$5.10
$5.10 - $5.10
$5.10

Volvo Penta Hexagon Nut – 955806

$9.98 - $9.98
$9.98
$9.98 - $9.98
$9.98
Only 4 left!

Volvo Penta OEM Hexagon Nut – 955806Genuine Volvo Penta OEM hexagon nut for Volvo Penta marine engine and sterndrive applications. Used to secure e...

View full details
$9.98 - $9.98
$9.98
$9.98 - $9.98
$9.98

Volvo Penta Hexagon Screw – 959968

$12.70 - $12.70
$12.70
$12.70 - $12.70
$12.70
Only 4 left!

Volvo Penta 959968 is a genuine OEM hexagon screw used in select Volvo Penta marine engine and sterndrive applications. Public Volvo Penta dealer l...

View full details
$12.70 - $12.70
$12.70
$12.70 - $12.70
$12.70

Volvo Penta Washer – 955893

$0.50 - $0.50
$0.50
$0.50 - $0.50
$0.50
24 in stock

Volvo Penta OEM Washer – 955893Genuine Volvo Penta OEM washer for use across Volvo Penta marine engine and sterndrive applications. Used as a seali...

View full details
$0.50 - $0.50
$0.50
$0.50 - $0.50
$0.50

PCM Nut R017072

$94.10 - $94.10
$94.10
$94.10 - $94.10
$94.10
Only 1 left!

Secure the transmission output flange and maintain proper drivetrain connection with the PCM 40A Transmission Output Flange Nut (1.23:1 Ratio). Thi...

View full details
$94.10 - $94.10
$94.10
$94.10 - $94.10
$94.10

PCM Cylinder Head -Exhaust Manifold Stud R031035.

$11.59 - $11.59
$11.59
$11.59 - $11.59
$11.59
11 in stock

Secure the exhaust manifold to the cylinder head with the PCM Cylinder Head / Exhaust Manifold Stud R031035. This genuine Pleasurecraft Marine (PCM...

View full details
$11.59 - $11.59
$11.59
$11.59 - $11.59
$11.59

PCM 6.0L Short Elbow -Manifold Stud R031036

$13.91 - $13.91
$13.91
$13.91 - $13.91
$13.91
Only 4 left!

Secure the exhaust elbow to the manifold with the PCM 6.0L Short Elbow / Manifold Stud R031036. This genuine Pleasurecraft Marine / Crusader OEM st...

View full details
$13.91 - $13.91
$13.91
$13.91 - $13.91
$13.91

PCM Exhaust Elbow - Manifold Stud R031037

$14.94 - $14.94
$14.94
$14.94 - $14.94
$14.94
Only 4 left!

Secure the exhaust elbow to the manifold with the PCM Exhaust Elbow / Manifold Stud R031037. This genuine Pleasurecraft Marine (PCM) OEM stud is de...

View full details
$14.94 - $14.94
$14.94
$14.94 - $14.94
$14.94