The Seiko Tuna: Understanding Screw Sizes For This Iconic Watch

The Seiko Tuna is a popular watch with a unique design. The watch has a shroud that is secured with three screws, giving it a suit-of-armour appearance. While the original screws are Allen head 1.5mm, some owners have opted for custom-made replacement screws, such as TORX screws, as the originals can be prone to stripping.

Seiko Tuna screw removal methods

Seiko Tuna watches are known for their stripped screws, which can be challenging to remove. Here are some methods to remove the screws successfully:

Using a Screw Extractor Kit:

Drill a small hole into the centre of the stripped screw with a drill bit. Choose a drill bit size that is smaller than the screw extractor. Place the extractor bit into the drill and set it to reverse. Apply pressure and slowly start spinning the drill until the screw comes out.

Using a Rubber Band:

Cut a rubber band and stretch it over the stripped screw. Insert a Torx bit or hex key over the rubber band, ensuring it covers any gaps between the screw head and the bit. Apply firm and equal force to the bit while slowly increasing torque. The rubber band method can help prevent damage to the screws.

Using Superglue:

Apply a drop of superglue to attach a hex key to the stripped screw. Allow the glue to dry, creating a firm connection. This method provides a stronger grip and makes unscrewing easier. To separate the hex key, soak the screw in nail polish remover for about 10 minutes.

Machining:

For complex cases, machining techniques can be used. This involves creating a custom clamp or washer to protect the watch crystal and case. The watch is then mounted on a rotary table to line up the broken screw. The screw is rough-machined with a cutter, and a screw extractor is used to remove the remaining threads.

It is important to exercise caution when attempting to remove stripped screws to avoid further damage. These methods can help increase the chances of successfully removing the screws from a Seiko Tuna watch.

Seiko Tuna screw replacements

Seiko Tuna owners have reported that the screws on the watch's shroud can be prone to stripping. This is due to the small size and softness of the screws, as well as the use of thread-locking compound by Seiko. While it is possible to order replacement screws from Seiko, some owners have opted to source their own replacements, or to use alternative methods to remove the stripped screws.

One method for removing stripped screws involves using a drill bit to create a hole for an extractor bit, which can then be used to remove the screw. Another approach is to use a rubber band to improve the grip of the screwdriver or bit, which can help to prevent slipping and reduce the chance of damage to the screw.

Some owners have chosen to replace the stock screws with custom-made or aftermarket options, such as those offered by Andy Stockley (tunascrews@gmail.com) or swiss2seiko. These replacements may offer advantages such as improved aesthetics or greater resistance to stripping. When choosing replacement screws, it is important to consider the correct size, which for the Seiko Tuna is M2.50 x 4mm with a 0.45mm pitch.

Seiko Tuna screw sizes

The Seiko Tuna is a popular watch with a unique design and serious dive watch capabilities. The watch has a shroud secured by three screws, giving it a suit-of-armour appearance. The screws are Allen head 1.5mm. However, some people have complained that these screws are too soft and strip easily. There are aftermarket shroud screws available from third-party sellers, such as Andy Stockley, who offers screws in different types and finishes. These aftermarket screws are cheaper than the stock Seiko screws and fit more flush with the case.

The Seiko Tuna has evolved over the years, and modern incarnations feature a monocoque titanium case, an L-shaped gasket, and a unique shrouded design. The watch is available in a variety of sizes, materials, and colours. The Tuna is known for its durability and functionality, with a water resistance rating of up to 600 metres.

The Seiko Tuna case has a distinctive design that may not appeal to everyone, but it is highly functional and well-suited for professional saturation divers. The watch is often praised for its build quality, with features such as drilled-through lug holes that make strap swaps easy. The Tuna also has a very accurate movement, with a battery life of over five years.

Overall, the Seiko Tuna is a unique and highly collectible watch with a rich history and an affordable price point. It is a must-have for any serious tool watch enthusiast or saturation diver.

Seiko Tuna screw tightening

Seiko's "Tuna" line of watches is a unique and eye-catching series of shrouded divers, known for their cylindrical slab of lugless casing. The Seiko Tuna is a robust and functional watch, designed with professional saturation divers in mind. Its distinctive design and impressive features have made it a sought-after collector's item.

When it comes to tightening the screws on a Seiko Tuna, it is important to exercise caution to avoid stripping the screws. The original screws on the Seiko Tuna are Allen head 1.5mm screws. These screws are prone to stripping, especially when over-tightened. It is recommended to use a high-quality screwdriver, such as the Bondhus 1.5 mm ball end screwdriver, to reduce the risk of stripping.

If a screw does become stripped, there are a few methods to remove it. One approach is to use a left-handed drill bit or an extractor bit to drill out the screw. This method should be handled carefully to avoid damaging the threads on the case. Another option is to use a rubber band technique, where a rubber band is stretched over the screw head and a bit is inserted, providing extra grip and torque for removal.

Additionally, aftermarket screws are available from vendors such as Andy Stockley, who offers screws in different types and finishes, including Torx and Phillips head designs. These aftermarket screws can provide a more secure option and a better fit than the stock screws.

When tightening the screws on your Seiko Tuna, it is important to find a balance between ensuring they are secure and avoiding over-tightening, which can lead to stripping. Using high-quality tools and considering aftermarket screws can help improve the experience and reduce the risk of damage.

Seiko Tuna screw alternatives

The Seiko Tuna is a highly collectible watch with a rich history and an affordable price point. Its unique design, with a shrouded case and integrated lugs, has made it a popular choice for watch enthusiasts. While the original Seiko Tuna watches are coveted by collectors and can be expensive, there are several alternatives and cheaper options available that offer a similar aesthetic. Here are some alternatives to consider:

• Swiko Baby Tuna and Sawtooth: These watches are similar in design to the Seiko Tuna, but may not have the same level of craftsmanship or specifications.
• Tauchmeister, Deep Blue, and Apeks: These brands offer shrouded dive watches that resemble the Seiko Tuna. They are cool in their own right and offer a good alternative to the real deal.
• Seiko SRP637: This watch is often referred to as a "baby tuna" or "tuna monster" due to its smaller size and similar design cues. It is a well-made watch that offers a lot of value for its price, typically retailing between $200 and $220.
• Seiko SUN: While not a direct alternative, the Seiko SUN series offers a similar dive watch aesthetic with a shrouded case. The dial design is different from the Tuna, but it may be a good option for those seeking a Seiko alternative.
• Cressi, Aqualung, and Tauchmeister: These brands offer a range of shrouded dive watches that may be cheaper alternatives to the Seiko Tuna.
• Deep Blue: Deep Blue offers a Tuna-style watch with a similar shrouded case design. It is a good option for those seeking a more affordable alternative.
• Aftermarket Shrouds: If you already own a Seiko SKX diver, you can purchase an inexpensive aftermarket shroud to give your watch a Tuna-like appearance. This is a cost-effective way to achieve the iconic Tuna look without breaking the bank.

These alternatives offer similar design elements and specifications to the Seiko Tuna at more affordable price points. However, it is important to note that the quality, craftsmanship, and durability of these alternatives may vary, and they may not carry the same level of prestige as the original Seiko Tuna.

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