Before you specify
Frequently Asked Questions
How much finer is P-5 than P-4 in practice?
Substantially. DIN 66399 caps P-4 at 160 mm² per particle and P-5 at 30 mm². The 51472's 1/13" x 9/16" particle measures about 28 mm², against roughly 126 mm² for the P-4 51464 in the same cabinet. In handling terms, a P-4 fragment can still carry a readable word or two; a P-5 fragment generally cannot carry more than a character. That difference is why P-5 appears in HR, medical and financial retention policies where P-4 is considered adequate for general commercial paperwork.
Will 11 x 17 tabloid fit?
Yes. The throat is 12 inches wide, so tabloid feeds flat with no folding, as do letter and legal. This is one of the practical reasons to choose the 51472 over the 51422, which shares the same P-5 cut but has a 10.25-inch opening that tabloid will not enter. Bear in mind that a tabloid sheet is twice the area of a letter sheet, so the 16-sheet rating effectively becomes an 8-sheet rating when you are feeding 11 x 17.
Does it shred CDs and DVDs, and to what level?
Yes — the 51472 is rated O-4 for optical media as well as P-5 for paper, and Dahle lists CDs, DVDs, credit cards, staples and paper clips among accepted materials. O-4 is the higher of the two optical ratings across this range; the P-4 models such as the 51464 and 51514 are rated O-3. Feed discs individually rather than mixed into a stack of paper, and do not feed hard drives, USB sticks or anything with a metal casing.
Is this shredder NSA approved?
No. NSA/CSS Specification 02-01 requires a maximum particle of 1 mm x 5 mm and listing on the NSA Evaluated Products List; the 51472 produces roughly 2 x 15 mm. A P-5 rating on its own never constitutes NSA approval, and no CleanTEC model in this range is an NSA-listed device. P-5 is entirely appropriate for commercial, medical, legal and financial confidentiality. Classified US government material requires a machine currently on the EPL, which is a separate and much more expensive category.
How often does the automatic oiler need refilling?
That depends on hours run, and Dahle does not publish a fixed interval. The EvenFlow Lubricator meters oil slowly and continuously rather than in bursts, so consumption is modest; check the reservoir monthly in normal office use and top up with Dahle shredder oil, item 20721 (12 oz) or 20722 (1 gallon). Do not substitute penetrating sprays or cooking oil — they leave residue that hardens on the cylinders. Running a P-5 head dry is the fastest route to a repair bill.
What bags does it take and how often will I change them?
Dahle item 20725, for 20 to 30 gallon bins, 100 to a box; bags are not supplied with the machine. At 16 sheets a pass, a small professional office typically gets a week or more from a bag, while a day spent clearing archive boxes will fill one on its own. The bin-full sensor stops the machine automatically, so you will not overpack it, but the sensor reads more reliably with a correctly sized bag than with a loose generic liner.
Is 53 dB quiet enough to sit near desks?
For most offices, yes. 53 dB is close to normal speaking volume and the machine sits on rubber shock mounts, so it does not transmit much through the floor. Combined with the dust filter, this is a shredder designed to live in occupied space rather than in a service room. If the office is genuinely quiet-critical, position it away from phone-heavy desks; the noise is steady rather than intermittent, which most people find easier to ignore.