New to these machines? See the letter opener buying guide. 10 current models from 3 manufacturers, as listed on each maker's website on October 18, 2026.
| Model | Type | Cutting method | Speed | Maximum thickness | Feed | Where to buy |
|---|---|---|---|---|---|---|
 Formax FD 442 | Desktop envelope opener (slitter) | Slits one side of the envelope end to end | Up to 200 envelopes per minute | Up to 3/16" (4 mm) | Bottom feed; approx. 15 envelopes per stack; photo-eye automatic start/stop | |
 Formax FD 452 | Desktop envelope opener (slitter) | Slits one side of the envelope | Up to 300 envelopes per minute | Up to 4 mm | Spring-loaded push arm; catch tray holds up to 80 #10 envelopes; resettable LCD counter | |
 Martin Yale 1632 | Automatic letter opener | Edge trim; cut width 1/8" (0.3 cm); blades fully enclosed | Up to 7,000 envelopes per hour | 3/16" (0.5 cm) | Automatic; 1.75" (4.4 cm) stack of standard business envelopes | |
 Martin Yale 62001 | Automatic letter opener | Edge trim; cut width 1/16" to 3/16" (0.8 to 4.8 mm) | Up to 17,500 envelopes per hour | 1/4" (0.6 cm) | Automatic; 6.0" (15.2 cm) stack, up to 154 envelopes | |
 Martin Yale PostMark 3056 | Automatic letter opener (milling cutter) | Milling cutter; depth of cut 0.7 mm (factory set), 0-3 mm (tool adjust) | 8,000 envelopes per hour (production); 24,000 per hour (theoretical) | .25" (6 mm) auto feed; .39" (10 mm) manual feed | Hopper capacity 300; feeder capacity 100 envelopes; mixed-thickness separator | |
 Martin Yale PostMark 3068 | Automatic letter opener (milling cutter) | Milling cutter; depth of cut 0.7 mm (factory set), 0-3 mm (tool adjust) | 14,000 envelopes per hour (production); 32,000 per hour (theoretical) | .25" (6 mm) auto feed; .39" (10 mm) manual feed | Hopper capacity 300; feeder capacity 100 envelopes; mixed-thickness separator | |
 Martin Yale PostMark 3078 | Automatic letter opener (milling cutter) | Milling cutter; depth of cut 0.7 mm (factory set), 0-3 mm (tool adjust) | 20,000 envelopes per hour (production); 36,000 per hour (theoretical) | .25" (6 mm) auto feed; .39" (10 mm) manual feed | Hopper capacity 300; feeder capacity 100 envelopes; mixed-thickness separator | |
 OPEX Omation Model 606 | Automatic letter opener (milling cutter) | Milling cutter; depth Eight settings, from 0.01" up to 0.125" (0.25-3.175 mm); no-cut setting for counting and sorting | Up to 40,000 envelopes per hour | Up to 0.5" | Self-adjusting automatic feeder for mixed envelopes | |
 OPEX Omation Series 210 | Desktop automatic letter opener (milling cutter) | Milling cutter; depth 0.01" to 0.07"; three cut-depth settings plus no-cut | Up to 400 envelopes per minute (6" envelope) | Up to 0.188" | Self-adjusting automatic feeder for mixed envelopes | |
 OPEX Omation Series 410 | Desktop automatic letter opener (milling cutter) | Milling cutter; depth 0.01" to 0.07"; three cut-depth settings plus no-cut | Up to 400 envelopes per minute (6" envelope) | Up to 0.188" | Self-adjusting automatic feeder for mixed envelopes |
Values are copied from each manufacturer's product page or spec sheet (linked on every model page) and shown in the maker's own units. Speeds measured differently (per minute, or with no unit stated) aren't converted and sort last. Amazon links appear only where we confirmed the listing is this exact model with a current offer; otherwise the link goes to the maker's page, which lists its dealers. We don't show prices.