Is Mason & Sullivan Still in Business?

Who Were Mason & Sullivan?

If you’ve ever shopped for clock parts or repaired a vintage clock, you may have come across the name Mason & Sullivan. Known for their detailed clock kits, beautiful movement replicas, and reliable parts, Mason & Sullivan held a strong place in the American clockmaking world throughout the mid-to-late 20th century. But if you’re searching for their products today, you might be wondering: Is Mason & Sullivan still in business?

Let’s break it down—who they were, what happened, and what your best options are now if you’re restoring a Mason & Sullivan clock or searching for compatible parts. Mason & Sullivan was a prominent American clockmaking company based in Huntington Station, New York. They gained national recognition for offering high-quality clock kits, dials, hands, and movements—mainly to hobbyists, woodworkers, and small clock shops. Their catalog included detailed instructions and templates for building reproduction 18th-century bracket and grandfather clocks, often styled after famous early American clockmakers like Simon Willard and Eli Terry.

One of their most notable achievements was partnering with German manufacturers, such as Hermle, to provide precision-made mechanical movements for use in their kits. These movements bore the Mason & Sullivan name but were typically stamped with German origin, ensuring high performance.

Are Mason & Sullivan Still Operating?

No, Mason & Sullivan is no longer in business.

The company ceased operations in the late 1980s or early 1990s, leaving behind a significant legacy but no continued product line. There is no official website, no customer service, and no new products being produced under the Mason & Sullivan brand today. Many of their remaining items—kits, movements, plans, and hardware—now circulate as vintage stock or collector’s items on auction sites and specialty restoration forums.

If you come across “new” Mason & Sullivan clock kits, they are either old stock from before the company closed or replicas built by hobbyists using original plans.

What Happened to Their Clock Movements?

Mason & Sullivan did not manufacture their own clock movements. Instead, they distributed movements made by reputable German companies, most commonly Hermle. These were often stamped with both the Mason & Sullivan name and the Hermle model number, allowing clockmakers to cross-reference replacements.

For example, a Mason & Sullivan movement labeled “MS-221” might correspond with a Hermle 340-020 movement. The gear layout, pendulum length, and chime setup were all standard to Hermle’s engineering specs.

Because of this partnership, it is usually possible to replace a worn Mason & Sullivan movement with a modern Hermle equivalent.

Can I Still Get Mason & Sullivan Replacement Parts?

Yes—sort of. While you cannot get newly manufactured Mason & Sullivan parts directly from the original brand, you can replace or repair most of their components using current German movements, parts, and hardware that match their specifications.

At Clockworks.com, we specialize in identifying and matching old Mason & Sullivan movements to their Hermle equivalents. This includes triple chime, time and strike, and time-only movements. We also carry a wide selection of hands, dials, pendulums, and other hardware compatible with their kits.

If you’re rebuilding an original Mason & Sullivan clock and unsure of the movement model, our team can help you identify it using photos, stamped codes, and case measurements.

What Should I Do If My Mason & Sullivan Clock Stops Working?

If your Mason & Sullivan clock stops running, loses time, or won’t chime, you’re likely dealing with a worn or dirty mechanical movement. Since most of their movements are decades old, oil dries out and friction builds up over time. You have two main options:

1. Replace the Movement – The best long-term solution. If your movement matches a modern Hermle equivalent, you can install a brand-new unit with decades of life ahead of it. This avoids the costly and time-consuming process of repairing worn-out bushings and pivots.
2. Repair the Original – If the movement has sentimental value or if it’s a rare type, you might choose to have it professionally cleaned, oiled, and repaired. We offer full restoration services for Mason & Sullivan movements at Clockworks, with expert-level handling of both Hermle and other vintage parts.

Either way, do not try to oil the clock yourself with household lubricants. This can damage the movement and make repairs more difficult down the road.

Are Mason & Sullivan Kits Still Worth Building?

Absolutely. If you come across a complete Mason & Sullivan clock kit—especially one with all the plans, wood parts, and hardware—it’s a great project for both hobbyists and serious clock collectors. These kits reflect a high level of craftsmanship and historical detail. With the right movement replacement and some careful wood finishing, you can create a beautiful timepiece with lasting value.

However, make sure the movement in the box is still viable. If it’s corroded, damaged, or incomplete, get in touch with us to help you find a replacement that will fit the original dimensions and chime rod layout.

What If I Don’t Know Which Movement I Have?

We help with that too. If your clock’s movement has numbers stamped on the back (e.g., “340-020” or “451-050”), we can usually match it to the correct replacement. If the movement only has Mason & Sullivan part numbers, send us a clear photo, and we’ll cross-reference it.

Be sure to provide:

• Movement dimensions
• Pendulum length (if applicable)
• Hand shaft length
• Chime type (Westminster, Whittington, etc.)
• Photos of the front and back of the movement

We regularly work with customers restoring Mason & Sullivan clocks and can walk you through the entire process.

Conclusion

Mason & Sullivan may no longer be in business, but their legacy lives on in the clocks built by hobbyists and collectors across the country. Whether you’re restoring a cherished family heirloom or building a vintage kit, you can still find compatible clock parts and movements with the right guidance.

At clockworks.com, we specialize in clock movement identification and replacement. Email us at clockworks@clockworks.com with your photos and questions, and we’ll help you bring your Mason & Sullivan clock back to life.

Updated on: 05/10/2025