Product Overview
Marine Stainless-Steel Diamond Garboard Drain Plug – Model ZB1902
RICHWITS ZB1902 lets you empty the bilge fast and seal it watertight for the season.
CNC-machined from solid 316 SS, molybdenum-stabilised for lifetime immunity to salt spray, brine and tropical humidity.
One-piece 4 mm thick diamond-flange body—20 % thicker than DIN 86261—handles grounding impact and high cantilever loads without flex.
Tapered M24 × 1.5 parallel thread with captive O-ring groove; supplied FKM (Viton) washer rated −30 °C to 200 °C, fuel & oil resistant.
Diamond footprint spreads load across 70 × 52 mm, stopping gel-coat cracks on thin hulls.
Dimension & Weight
| CODE | Thread | A mm | B mm | C mm | D mm | E mm | F mm | G mm | WT kg | Hull Thickness |
| ZB1902 | M24 × 1.5 | 70.0 | 41.5 | 52.5 | 25.5 | 4.0 | 31.0 | 5.2 | 0.168 | 6–25 mm |
Key Features & Benefits
316 SS One-Piece Body – zero weld seams, zero rust, zero electrolysis.
Diamond Flange 70 × 52 mm – spreads load, eliminates gel-coat cracks on thin hulls.
M24 × 1.5 Parallel Thread – self-locking; no thread sealant needed.
4 mm Wall Thickness – survives impact from trailer rollers or gravel knock.
FKM O-Ring Included – chemical-proof against diesel, oil, coolant; reusable 50+ cycles.
Low-Profile Head 5.2 mm – keeps plug clear of trailer bunks or keel rollers.
Knurled & 24 mm Hex – hand-tighten in emergencies, spanner for final 1/4 turn.
Lightweight 168 g – 30 % lighter than bronze equivalents—cuts shipping cost.
Usage Scenarios
Garboard / Transom Drain – primary bilge emptying on skiffs, RIBs, sailboats.
Live-Well Drain – diamond flange seats flush on sloped ice-box floors.
Engine-Box Scupper – high-temp FKM seal handles turbo coolant spills.
Deck Drain Blank – temporary seal for pressure-wash test or winter lay-up.
Why Choose RICHWITS
Factory-Direct – wholesale & retail welcomed, 25 % cost saving vs. bronze equal.
In-Stock – 3 000 pcs ready, MOQ 100 pcs, 48 h dispatch.
Fast Logistics – FedEx/UPS/DHL global 3-7 day delivery.
OEM/ODM – custom thread, shank length or laser-logo within 10 days.
Test Certificates – material mill cert, 48 h salt-spray, torque-seal report supplied free.
FAQ
Q1: Will 316 SS really never rust?
A1: Correct—2-3 % Mo gives lifetime immunity to chlorides; polish yearly to keep the mirror shine.
Q2: What hull thickness will it seal?
A2: M24 thread + 2.5 mm O-ring seals 6–25 mm thick hulls; longer shanks on request.
Q3: Do I need thread sealant?
A3: Not for parallel thread + O-ring; PTFE tape optional on aluminium to stop galvanic attack.
Q4: Can I weld the diamond flange after installation?
A4: Yes—316L composition allows TIG field welding; polish heat tint with included restore pad.
Q5: Are spare O-rings available?
A5: Yes—10-pack of FKM O-rings, MOQ 50 packs, $0.15 each.
Q6: Do you offer test certificates?
A6: Mill certificate for 316 SS, salt-spray report, and torque-seal certificate supplied free on request.
Packing & Delivery
