Apply Discount Code
CHU3K70073PB
Union 3K70 5 Detainer Sashlock 73mm Brass (Chubb At Heart)
Main image
Click to view image in fullscreen
![]()
Union (Chubb At Heart) B-3K70 73mm Brass 5 Detainer Mortice Lock 2K
In stock
Delivery Information
| Delivery Time Frame | Delivery Information |
| Next Working Day By 1PM | When an order is placed by 3pm for next working day on certain items |
| Standard Delivery | Usually delivered in 2 to 4 working days |
| Delivery Charges | |
| UK Mainland | Prices start at £3.95 for very small items, £6.50 for small, £9.50 for medium and £20 for large/long items |
| Scottish Highlands & Islands, Northern Ireland & Ireland | Prices from £30, please see our delivery page for more info. |
View Delivery Information
£269.59
Incl. VAT
(Save 31%)
£224.66
Excl. VAT
£187.07
Incl. VAT
£155.89
Excl. VAT
Incl. VAT
Excl. VAT
Incl. VAT
Excl. VAT
Price is for/per each
-
+
See our full range:
Description
Union 3K70 5 Detainer Sashlock 73mm Brass (Chubb At Heart)
Security is the foundation of any well-protected property. When you choose the Union 3K70 5 Detainer Sashlock 73mm Brass (Chubb At Heart), you are investing in a legacy of engineering excellence. This premium mortice lock is designed for those who refuse to compromise on the safety of their homes or commercial premises.
Featuring the iconic Chubb at heart technology, this device represents a pinnacle in mechanical locking systems. It combines robust construction with intricate internal mechanics to provide a formidable barrier against unauthorized entry. Whether you are upgrading a residential entrance or securing an office door, this hardware delivers peace of mind.
Advanced Security Features and Construction
The engineering behind this unit focuses on total structural integrity. The use of a five detainer system elevates the security profile far beyond traditional lever designs, providing a much higher number of potential key combinations that make lock manipulation significantly more difficult for intruders.
- The construction incorporates force resistant capabilities that act as a deterrent against physical attack methods like drilling or heavy impact.
- Engineered with anti-pick technology, the internal mechanisms are designed to frustrate even determined attempts to bypass the locking sequence without the correct key.
- The inclusion of anti-saw security features ensures the deadbolt can withstand sustained cutting attempts, maintaining your property boundaries effectively.
- A 14mm bolt throw provides deep engagement into the frame to ensure that the door remains held firmly in place even under extreme pressure or attempted forced entry.
Mechanical Physics and Operational Resilience
When you operate this lock, you are engaging a sophisticated arrangement of internal components that prioritize long term reliability. The deadbolt is crafted from high grade brass and reinforced with hardened steel rollers, a combination that minimizes internal friction while maximizing resistance to external shear forces.
The physics of the five detainer movement ensures that the locking mechanism operates with a smooth, precise action. By distributing the mechanical load across these detainer plates, the system avoids the premature wear often seen in cheaper alternatives. Because the follower is manufactured from high quality sintered iron, it offers excellent tolerance to repeated cycles of torque applied by the lever handle.
This design prevents component flex, which is the primary cause of hardware failure in lower quality locks. By mitigating the effects of thermal expansion and structural movement in timber doors, this equipment remains reliable through seasonal changes in temperature and humidity.
Step By Step Operational Workflow
Interacting with this hardware is an intuitive experience designed for everyday convenience and security. To lock the door from the outside, the user inserts the key into the escutcheon and rotates it to drive the deadbolt into the box strike. This motion causes the detainer plates to align, allowing the bolt to move fully across and engage with the frame.
To unlock, the process is simply reversed, allowing the user to withdraw the bolt while maintaining full control over the door. When the door is in the closed but unlocked position, the latch bolt provides temporary retention. A simple downward movement of the lever handle withdraws this latch, enabling the user to enter or exit with minimal physical effort.
The precision of the internal components ensures that there is no 'stickiness' or misalignment, even after years of continuous service. Every movement feels solid and reassuring, demonstrating the superior quality of the Chubb at heart heritage found within this specific model.
Ergonomic Health and Safety Compliance
Modern building standards require hardware that balances security with the safety of occupants. This mortice lock is fully assessed under the EN 1634-1 standard, confirming its suitability for use on 60 minute timber fire doors. This means that in the event of an emergency, the structural integrity of the door assembly remains intact, protecting both the structural envelope and the inhabitants.
From an ergonomic perspective, the smooth operation of the lever handle and key mechanism reduces physical strain on the wrists and hands of users. For environments where accessibility is a priority, the refined action of this equipment ensures that individuals of all strength levels can operate the door with ease and confidence. By reducing the force required for operation, you minimize the risk of repetitive strain injuries in high traffic areas.
Commercial ROI and Long Term Value
Investing in high quality door furniture is a decision that pays dividends over time. While cheaper locks may seem economical at the point of purchase, they often require frequent replacement due to material fatigue and mechanical failure. Choosing this Union 3K70 5 Detainer Sashlock minimizes your maintenance overheads significantly.
The durability of the brass forend and the silver powder coated steel case ensures that the lock remains aesthetically pleasing and mechanically sound for many years. This resilience protects your valuable assets by maintaining a consistent security standard throughout the building lifecycle. When you account for the reduced need for call-out services and replacement parts, the cost of ownership becomes remarkably low.
Furthermore, installing professional grade hardware can have a positive impact on your insurance premiums. Many insurers recognize the effectiveness of Chubb at heart technology and may offer more favorable terms for properties protected by this caliber of security hardware.
Still uncertain about your technical requirements? Our expert team is ready to assist you. If you are not sure if this mortice lock is right for your requirements please contact our friendly team today for tailored advice on your door hardware installation.
Technical Specifications
This table outlines the essential dimensions and physical properties of the device to help you plan your installation with complete accuracy.
| Parameter | Detail |
|---|---|
| Case Size | 73mm (3 inches) |
| Backset | 44mm |
| Faceplate Dimensions | 200mm x 25mm |
| Case Height | 148mm |
| Centres | 56mm |
| Deadbolt Material | Brass with hardened steel rollers |
| Latch Bolt Material | Brass |
| Follower Material | Sintered Iron |
| Case Finish | Silver powder coat |
| Forend Finish | Polished brass |
| Keys Supplied | 2 |
Installation Considerations
When preparing to install this Union 3K70 5 Detainer Sashlock, ensure that your timber door is of sufficient thickness to accommodate the case dimensions, which are specifically designed for doors up to 50mm thick. The universal design allows for application on doors hinged on either the left or the right side, providing excellent versatility for property managers and locksmiths.
The box strike provided is finished to match the polished brass forend, ensuring a cohesive and professional appearance across the entire door edge. Whether you are performing a new installation or replacing existing mortice locks, the standard dimensions make integration straightforward. We recommend using a professional joiner or locksmith if you are inexperienced with timber door modification, as a precise cutout is essential for the longevity of the mortice mechanism.
By adhering to these installation best practices, you guarantee that the anti-pick and anti-saw features function exactly as intended by the manufacturer. A secure fit prevents unauthorized manipulation and ensures that the bolt engages fully with the strike plate, fulfilling the security promise of this iconic design.
Specification
| Manufacturer | Union |
|---|---|
| Dimensions | 148 (H) x 73 (D) |
| Guarantee | 10 Year |
| Lock Type | Mortice Sashlock |
| Lock Operation | Lever |
| Lock Backset | 44mm |
| Lock Centres | 57mm |
| Follower Size (mm) | 8 |
| Faceplate Width | 25mm |
| Environmental Suitability | All |
| Mechanism | Sashlock |
| Door Material Suitability | Wood |
| Max Door Thickness (mm) | 50 |
| Forend Finish | Polished Brass |