Lum-Tec Combat B70 Automatic | USA Assembled Blue Dial Field Watch with MDV Lume

The Combat B70 is part of Lum-Tec's Combat B series, the field watch line Lum-Tec has kept refining since the first Combat B1 arrived in 2007. Lum-Tec says Combat B watches have been battle tested in real military applications and in environments from deserts to freezing mountaintops, and that they are trusted by pilots, ground soldiers, snipers and mountain climbers. Lum-Tec says the Combat B is comfortable on the wrist, legible and accurate, and that its anti-shock capability is well proven in the field.

The B70 pairs the automatic Combat B with a blue dial. Its Japanese Miyota 9015 beats at 28,800 per hour, winds by hand and hacks for precise setting, and Lum-Tec regulates it in six positions in-house; a sapphire window in the caseback shows it off. The forged, heat-treated 43 mm case is left in uncoated bead-blasted steel, and the matte blue dial and diamond-cut hands use grade A Swiss BGW9 Super-Luminova as part of Lum-Tec's MDV® luminous technology. It is rated to 200 meters, comes with blue and gray nylon straps, and is limited to 500 pieces.

As an authorized Lum-Tec dealer, The CGA Company sells the B70 new, never pre-owned, with free USA shipping. Two nylon straps come in the box, and production is a limited, numbered series of 500.

Specifications

• Case width: 43 mm, forged 316L surgical-grade stainless steel, heat treated for hardness
• Thickness: 13.6 mm including the domed sapphire
• Lug to lug: 51.5 mm (steeply curved lugs; Lum-Tec says it wears like roughly 46-47 mm)
• Lug width: 22 mm
• Finish: Bead blasted, with anti-fingerprint coating
• Water resistance: 200 meters
• Movement: Japanese Miyota 9015 automatic, 28,800 BPH, hand winding and hacking seconds
• Regulation: Adjusted in six positions in-house
• Shock protection: Anti-shock movement mounting system
• Crystal: Curved sapphire with military-grade DLC anti-reflective coating on the inside
• Caseback: Threaded 316L steel with a sapphire window
• Crown: Threaded, double Viton® seals
• Gaskets: Viton®
• Dial: Matte blue (Pantone 2376C) with A-grade BGW9 Super-Luminova
• Hands: Diamond-cut, filled with A-grade BGW9 Super-Luminova
• Lume: MDV® luminous technology on dial and hands
• Straps included: 2 heavy-grade nylon military straps (one blue, one gray) with bead-blasted hardware
• Warranty: 2-year limited warranty
• Edition: Limited and numbered, 500 pieces worldwide
• Assembly: Designed, assembled by hand and fully tested in Mentor, Ohio

Construction

The case is forged rather than cast from 316L steel, then heat treated. Lum-Tec says forging gives about 37% more fatigue strength than a typical cast case, and that the bead-blast finish creates a micro work-hardened surface that improves scratch and ding resistance by 8-10%. A vapor-deposited anti-fingerprint layer seals the finish against smudges.

The thick, slightly domed sapphire sits in a Hytrel mount and has AR coating on its inner face to cut glare. Silicone-lubricated double Viton seals protect the crown and the threaded caseback. Lum-Tec says the sealing is tested to 30% beyond the 200 m rating.

Heat treatment does two jobs on this case: it keeps the steel stable while it is being forged and hardens the surface once finishing is done. The glare-cutting layer on the inside of the sapphire is a military-grade DLC anti-reflective coating. The case seals are there to stand up to salt water, chemicals and very hot or very cold conditions, not just water pressure, and if the watch is dropped on a hard floor or knocked against a wall, the anti-shock mount lets the movement absorb the hit.

Fit and Straps

Because the lugs turn down sharply, the 51.5 mm lug-to-lug wraps around even small wrists. Each of the two heavy nylon straps, one blue and one gray, runs under both spring bars, so the watch stays on the wrist if one spring bar fails.

Lum-Tec says its nylon straps are more durable than typical straps of this type and are designed for easy adjustment, a secure fit and minimal weight on the wrist.

MDV® Lume

The dial is printed with more than 30 layers of A-grade BGW9 Super-Luminova over a reflective base, so the light is pushed out toward the wearer instead of back into the dial. The hands carry the same material. Lum-Tec says RcTritec in Switzerland verified its dials as top Super-Luminova performers.

What Reviewers Say

"As a tool watch, the Combat B70 is a beast." ... "Suffice it to say that the lume is very good and even."

Ariel Adams, aBlogtoWatch, September 26, 2026

Lifetime Service

For as long as you own the B70, Lum-Tec provides free timing adjustment, seal cleaning and pressure testing in Ohio. Lum-Tec says it regularly sees its watches come back for service after 15 or more years of use, and it puts what it learns from them into new designs. Lifetime services are provided by Lum-Tec under Lum-Tec's terms, not by The CGA Company; for service, contact service@lum-tec.com.

Hand Assembled and Tested in Mentor, Ohio

Lum-Tec says its watches are designed and engineered in Ohio from the ground up, and every Combat B70 is hand assembled and individually tested in Mentor, Ohio, using international and domestic components; the movement in this model is the Japanese Miyota 9015 automatic. After assembly, the movement's timing is adjusted in six positions. Lum-Tec says that since 2007 it has produced watches for more than 100 brands around the world, the U.S. government and SWAT teams.

Frequently Asked Questions

What movement is inside?
A Japanese Miyota 9015 automatic running at 28,800 BPH, with hand winding and hacking seconds. Lum-Tec regulates it in six positions in-house.

Where is the Combat B70 assembled?
Lum-Tec hand assembles and tests every Combat B70 in Mentor, Ohio, using international and domestic components. The movement is the Japanese Miyota 9015 automatic. Its timing is adjusted in six positions after assembly.

How water resistant is it?
It is rated to 200 meters, and Lum-Tec says its sealing is tested to 30% beyond that rating.

Will it fit a smaller wrist?
Usually, yes. The lugs curve down steeply, so the 51.5 mm lug-to-lug wears like roughly 46-47 mm, according to Lum-Tec.

What comes with it?
Two heavy nylon military straps (blue and gray), a 2-year limited warranty, and Lum-Tec's lifetime timing adjustment, seal cleaning and pressure testing. It is one of 500 numbered pieces.