Tajima makes precision hand tools for contractors who measure twice and cut once. Japan’s largest manufacturer of hand tools, they’ve been at it since 1909. Their lineup includes utility knives, chalk reels, caulk guns, and replacement blades — the sharp, accurate basics that live in every contractor’s toolbox.
The Tools That Matter
Tajima’s AC-700B utility knife weighs 8.8 oz in die-cast aluminum, uses SK-120 high-carbon steel blades at 0.7mm thickness, and locks automatically. That auto-lock mechanism means one-handed operation when you’re holding materials with the other hand. The handle stores 2 spare blades internally, and there’s a snap-off tool built into the end cap. Smart design for pros who burn through blades.
The knife takes 1-inch wide blades with either 7 or 13 snap-off points. Rock Hard designation means Japanese-style multi-step tempering — these blades hold an edge longer than the cheap ones at the checkout counter. At 0.7mm thickness, they’re stiff enough for scoring drywall without flexing.
| AC-700B Specifications | Value |
|---|---|
| Blade width | 25mm (1 inch) |
| Blade thickness | 0.7mm |
| Blade material | SK-120 high-carbon steel |
| Weight | 8.8 oz (250g) |
| Overall length | 6 inches |
| Handle length | 5 inches |
| Blade storage | 2 spare blades |
Chalk Systems Built for Weather
Montana contractors know what happens to standard chalk lines in snow or rain — they disappear. Tajima’s H2O Repellent chalk uses water-repellent granules that resist washing out. The formulation stays visible on wet lumber and concrete when other chalks turn to mud.
Their CR301 chalk reel runs a 5:1 gear ratio that rewinds up to 4 times faster than standard reels. That’s 100 feet of line cranking back in seconds, not minutes. The 1.0mm extra-bold line shows up on rough surfaces where thin lines get lost. Jam-free spool mechanism means it actually works when covered in concrete dust.
| CR301 Chalk Reel Specifications | Value |
|---|---|
| Line length | 100 ft (30m) |
| Line thickness | 1.0mm (extra bold) |
| Gear ratio | 5:1 |
| Rewind speed | 4x faster than standard |
| Chalk capacity | 3.5 oz (100g) |
| Weight | 6.7 oz |
Cold-Weather Caulk Performance
The CNV-900SP18 caulk gun delivers an 18:1 thrust ratio — 20% more force than standard guns. When polyurethane sealants turn to peanut butter at 20°F, that extra thrust matters. The 360° rotating handle lets you work around obstacles without twisting your wrist.
Built for 1-quart cartridges with a 13.5-inch barrel, it handles the large-format tubes contractors use for big sealing jobs. The long puncture pin actually reaches the bottom of thick cartridge seals. Steel body construction — not the plastic junk that cracks when dropped.
| 18:1 Caulk Gun Specifications | Value |
|---|---|
| Model | CNV-900SP18 |
| Thrust ratio | 18:1 |
| Thrust advantage | 20% more force |
| Capacity | 1 quart (900ml/32 oz) |
| Barrel length | 13.5 inches |
| Handle rotation | 360° |
| Weight | 2.5-3.0 lbs |
The Company Behind the Tools
TJM Design Corporation, formerly Tajima Tool Corporation, started manufacturing steel tape rules in 1909. They’ve grown into Japan’s largest hand tool manufacturer. The company added a flooring division in 1952, though their hand tools remain the core of what Montana contractors see on jobsites.
Their mission centers on “innovation with a timeless spirit that honors creativity” — marketing speak for making tools that work. After 115 years, they’ve figured out what matters: sharp blades, smooth mechanisms, and materials that survive jobsite abuse.
Worth Your Money?
Tajima targets professional contractors, not weekend warriors. The AC-700B knife runs circles around throwaway knives for blade retention and one-handed operation. Their water-repellent chalk actually repels water — revolutionary concept. The 18:1 caulk gun pushes thick sealants that cheaper guns can’t budge in cold weather.
Skip Tajima if you’re buying tools for occasional weekend projects. Their precision matters when you’re burning through blades daily, snapping hundreds of chalk lines, or pushing tubes of sealant in freezing conditions. Professional tools for professional budgets — exactly what they’ve built their reputation on for over a century.
Frequently Asked Questions
Q: What makes Tajima utility knife blades different from standard blades?
Tajima uses SK-120 high-carbon steel with Japanese-style multi-step tempering (their “Rock Hard” designation) in 0.7mm thickness. The 1-inch wide blades come in 7-point or 13-point snap-off configurations and hold an edge longer than standard utility blades.
Q: Will Tajima chalk lines work in wet conditions?
Yes, Tajima’s H2O Repellent chalk uses water-repellent granules specifically formulated to resist washing out in rain or on wet surfaces. The dark red chalk creates sharp, bold lines that stay visible on wet lumber and concrete where standard chalks disappear.
Q: How fast does the Tajima CR301 chalk reel rewind?
The Tajima CR301 uses a 5:1 gear ratio that rewinds up to 4 times faster than standard chalk reels. It handles 100 feet of 1.0mm extra-bold line and features a jam-free spool mechanism designed to work when covered in construction dust.
Q: What size caulk tubes does the Tajima 18:1 caulk gun handle?
The Tajima CNV-900SP18 caulk gun handles 1-quart (900ml/32 oz) cartridges with its 13.5-inch barrel. The 18:1 thrust ratio delivers 20% more force than standard caulk guns, making it effective for thick sealants in cold weather.
Q: How many spare blades can you store in the Tajima AC-700B knife?
The Tajima AC-700B utility knife stores 2 spare blades inside its die-cast aluminum handle. The knife also includes an integrated snap-off tool in the end cap for breaking blade segments when they dull.
Q: Is Tajima a Japanese company?
Yes, Tajima is TJM Design Corporation (formerly Tajima Tool Corporation), founded in 1909 as a manufacturer of steel tape rules. They’ve grown into Japan’s largest hand tool manufacturer and added a flooring division in 1952.
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