Commercial 4 1/2 Door Hinges
Stainless Steel Self Closing
Waterson’s commercial 4 1/2 door hinges are durable and versatile, designed for high-traffic areas and fire-rated doors. Fully adjustable, the 4 1/2 hinges provide precise control over closing speed and backcheck, ensuring smooth operation. Made from high-quality materials, these hinges are built to withstand frequent use and comply with ADA standards for speed control, closing force, and door clearance.
Most Frequently Asked Questions
Speed control, low opening force, weather resistance, hold open, heavy-duty, and more. Learn about our 7 innovative features.
Read about the differences of Mechanical Only Self Closing and Hydraulic Hybrid Soft Close differences.
Waterson 4.5 Inch Commercial Hinges Type Table
| Hinge TYPE | MECHANISM | FUNCTIONS |
| DS | Top: Spring Power Bottom: Spring Power |
Dual door closing force |
| SA1 | Top: Spring Power Bottom: Mechanical Friction |
Door closing force & latch speed control |
| SA | Top: Spring Power Bottom: Mechanical Friction |
Door closing force & swing speed control |
| SB | Top: Spring Power Bottom: Hold-open Feature |
Door closing force & hold the door at 85°+/-5° |
| HA | Top: Hydraulic Damping Bottom: Mechanical Friction |
Both swing&latch speed control depends on settings |
| HS | Top: Hydraulic Damping Bottom: Spring Power |
Door closing force &Both swing&latch speed control depends on settings |
Each hinge has two distinct functions, one adjusted from the hinge top, and the other from the bottom. NOTE: hinges can be inverted.
| Door Size | Product SKU Full mortise 4.5*4.5 |
FEATURES Door Range ≤ 120° |
Mechanical Only – M |
Hinge Qty Hinge Type |
Finish | ||
|---|---|---|---|---|---|---|---|
| Self-closing | Fluid Motion | 90°Hold-open | |||||
| 1-3/4″ < 6’-0 x 4′-0≤ 150 lbs |
K51M-450-A2 | ● | M | 2 hinges/door (SA.SA1) |
In Stock
Special Order
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| K51M-450-B2 | ● | ● | H | 2 hinges/door (DS.HA) | |||
| 1-3/4″ < 7’-0 x 4′-0≤ 260 lbs |
K51M-450-A3 | ● | M | 3 hinges/door (SA.SA.SA1) | |||
| K51M-450-B3 | ● | ● | H | 3 hinges/door (DS.HA.SA1) | |||
| K51M-450-C3 | ● | ● | M | 3 hinges/door (SB.SA.SA1) | |||
| K51M-450-D3 | ● | ● | ● | H | 3 hinges/door (DS.HA.SB) | ||
| 1-3/4″ < 8’-0 x 4′-0≤ 260 lbs |
K51M-450-C4 | ● | ● | M | 4 hinges/door (SA.SB.SA.SA1) | ||
| K51M-450-D4 | ● | ● | ● | H | 4 hinges/door (DS.SB.HA.SA1) | ||
| 1-3/4″ < 8’-0 x 4′-0≤ 330 lbs |
K51M-450-A4 | ● | M | 4 hinges/door (DS,SA,SA,SA1) | |||
| K51M-450-B4 | ● | ● | H | 4 hinges/door (DS.SA.HA.SA1) | |||
1. We provide additional door stop ( at 90°) features for all models. Email: hinges@watersonusa.com to request a quotation
2. Click here to learn more about Waterson hinge types (SA,SA1,SB,…)
3. Click here to learn more about closing types, or watch video
4. Please contact us directly concerning doors over the above specifications.
Various businesses, including hotels, schools, and retail stores, choose Waterson self-closing 4 1/2 door hinges for durability, design, and sustainability.
Technical Drawing for 4,5″ x 4,5″
| US AREA | |||||
|---|---|---|---|---|---|
| Full Mortise Self-closing Hinge – Stainless Steel – Commercial Grade – 4-1/2″x 4-1/2″ (K51M-450) | DWG | X_T | |||
| Full Mortise Self-closing Hinge – Stainless Steel – Commercial Grade – 4-1/2″ x 4-1/2″ -1/4 R (K51M-450-1/4R) | DWG | X_T | |||
| Full Mortise Self-closing Hinge – Stainless Steel – Commercial Grade – 4-1/2″ x 4-1/2″ -5/8 R (K51M-450-5/8R) | DWG | X_T | |||
Code Compliance
| ANSI/BHMA A156.7 Full Mortise Template | ||
| ANSI/BHMA A 156.17 Grade 1 Single Acting Hinge | ||
| ANSI/ICC A117.1 ADA Accessibility | ||
| UL Listed for ANSI/UL 10B and UL 10C, CAN/ULC S104 up to 3 hours | ||
| NFPA 80 National Fire Protection – Fire Door Assembly | ||
| NEPA101 National Fire Protection – Self Closing Device | ||
| ANSI/BHMA A 156.18 Finishes |
Waterson 4 1/2 Door Hinges are easily adjustable and re-adjustable simply with two Allen wrenches in just minutes. Follow our procedure to get the optimal closing experience.
| Installation Guide | Click Here | ||
| Set A3 ( SA.SA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set B3 ( DS.HA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set C3 ( SB.SA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set D3 ( DS.HA.SB ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set A4 ( DS.SA.SA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set B4 ( DS.HA.SA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set C4 ( SB.SA.SA1.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
| Set D4 ( DS.SB.HA.SA1 ) – Waterson self-closing hinge adjustment manual | Download | ||
How to Adjust
Please note that Waterson offers a variety of product codes including K51M, K51SWRH, K51P, K51L, and K51GG, among others. However, the adjustment process remains consistent and is categorized based on codes A, B, C, and D. Below are the videos on how to adjust:
K51M-A3 (SA.SA.SA1)
K51M-B3 (DS.HA.SA1)
K51M-C3 (SB.SA.SA1)
K51M-D3 (DS.HA.SB)
Choose either mechanical self-closing spring-loaded hinges or hydraulic hybrid soft-close ones depending on your particular closing needs.
Code Compliant
ADA Opening Force: No more than 5 lbs
ADA Closing Speed: At least 5 seconds to go from 90° to 12°
No More In-Floor Installation
Well-controlled Closing Speed