Inspired by the the Sai, a traditional Okinawan melee weapon, the UPK-D1 Pocket Sai is a modern implementation optimized for compact and safe carry. This is not far from actual Sai history where Sai could be concealed within the loose fitting clothing of the time, the Kimono, and carried in sets of 2 or 3, of which various 2 handed and throwing techniques were used.
The UPK-D1 Pocket Sai is designed to retract to sheat the 'Saki' or Sai tip, when unlocked with the press of a button located on the base of the blade, the handle slides to eclipse the monouchi (main blade) and create an integral sheath when closed . This makes each Sai a contained solution with no need to return it to an accessory sheath. In its closed form, the Pocket Sai offers a formidable blunt striking weapon weighing as much as half a pound of hardened martensitic Stainless Steel.
I designed the Pocket Sai with faceted bevels along its blade to give it an intentionally ominous appearance. In any confrontation you do not want a fair fight, you want every advantage, you want the biggest force multiplier you can attain. The Pocket Sai doubles in length to 12" OAL. The best defense to unavoidable confrontation is a strong deterrent. Deployed with confidence the Pocket Sai would give any would be attacker a significant reason to consider self preservation.
*As with any tool, it can only be as effective as the user's training and preparation. Train hard, be a hard target. A hard target is a predator's last choice.
While a traditional Sai is not a sharp edged weapon, Pocket Sai come to a distinct point to offer an effective pierce. The beveled mounuchi opens the option to grind the bevels to create a double edged dagger for those seeking it, with the yoku(guards) removed this implement becomes the UPK-D4.
The Yoku, or side prongs are arguably the most recognized feature set of the Sai, and a significant effector in practical applications. Martial art techniques utilize the Yoku to achieve opponent weapon control and highly effective pinch, hold, and puncture techniques.
I offer the D-Series tools in several materials for user's desired application.
RED Polymer composite - 9 ksi tensile strength - Training and Fun, this is the most durable "plastic" I am aware of. Made with 50% Glass filled Nylon, this plastic is durable enough to be used in the firearms industry to make the guns frame and its core. Dependable and long wearing! This is not advised for self defense, while very durable, its possible to break Polymer components with your bare hands.
BLACK Hard-coat Anodized 7075-T6 Aluminum - 74 ksi tensile strength - Strong EDC Capable with very high strength to weight ratio. This is the strongest Aluminum alloy I am aware of being practical to machine and fabricate into a Pocket Sai. This alloy is present in only the strongest Aluminum applications, used when strength and lightweight are both high priorities. This particular flavor spans into steel strength territory overtaking mild steels and even annealed stainless steels.
SS 440A Hardened Stainless Steel - 220-260 ksi tensile strength - This is the Toughest material I make with. This is the best evolution of the Pocket Sai and its variants when seeking a tough reliable weapon. It will last the longest and accept the most brutal forces performing to bend before break when pushed beyond its yield strength. I recommend this for throwing and and everything else.
SS 154CM / 14C28N / CPM MagnaCut - 300 ksi and beyond - These materials range in premium strength qualities and hardness, and I occasionally offer them fully fabricated in-house using 100% US made techniques. These are reserved for the blade connoisseur seeking the most refined steels and material qualities.