Paper shredder types and ratings

Paper shredders cut documents in one of two ways. Strip-cut shredders slice documents into long, narrow strips. Unless the strips are very narrow, experts say it's fairly easy to reassemble them into the original document, and the strips are bulky. Instead, most reviews recommend crosscut shredders, which cut the strips into short lengths (those that cut the smallest pieces are sometimes called confetti-cut shredders). Micro-cut shredders render documents into even tinier diamond-shaped bits, but the extra cutting slows the process and requires more power.

Paper shredder specifications often include a security level based on the DIN 32757 standards (established by the Deutsches Institut fŸr Normung or, in English, the German Institute for Standardization), and by the U.S. federal government. Ratings used in the United States range from 1 to 6, with 6 being the most secure and generally used for top secret classified documents.

For homes and small offices, experts such as New York Times technology writer Sam Grobart recommend Level 3 crosscut paper shredders. Crosscut models earn the Level 3 rating by shredding paper into pieces no larger than 4 mm wide by 50 mm long (the shorter the better) -- or approximately 0.175 inches wide by 2 inches long.

Manufacturers also rate paper shredders based on how many sheets they can shred per pass -- that is, in one bundle. Ratings for personal paper shredders for home- and small-office use usually range from about six to 15 sheets at a time. However, expert reviewers and user reviews all say that those manufacturer capacity ratings are a fantasy -- partly because paper comes in so many different thicknesses. It's a wise idea to halve the stated capacity number for practical purposes.

Paper shredder specifications

In addition to security level, cutting type and maximum sheets per pass, manufacturers usually provide other specifications useful in choosing a paper shredder:

Speed: how fast a bundle of paper is shredded, in feet per minute

Duty cycle: the number of minutes the shredder can work continuously, plus the number of minutes in the cool-down period before it can be operated again without shortening its life

Maximum passes per day: usually much higher for paper than for credit cards (or, for models rated for them, data discs)

Noise level

Not all manufacturers provide all these specifications for their paper shredder models. In many cases, finding the maximum passes per day requires checking the owner's manual or calling the manufacturer.

Paper shredder features to consider

Reviewers say to look for the following when shopping for a paper shredder:

  • Crosscut and micro-cut paper shredders provide more security than strip cutters. A strip cutter can provide useful packing material or animal bedding, but experts recommend a Level 3 crosscut paper shredder for most home and small business users.
  • Consider what you need to shred. Do you plan to shred unopened envelopes of junk mail? How about multi-page documents fastened with staples or paper clips? Do you have data backup discs (CDs or DVDs) with sensitive data that you'd like to shred? If so, experts say you'll need to look for a heavy-duty shredder that can destroy more than just paper.
  • Shredders are noisy. Experts say that sound doubles for every five-decibel increase. So a shredder rated at 58 to 60 decibels is twice as quiet as one rated at 65 decibels, which in turn is about twice as loud as one rated at 70 decibels. We even found a shredder rated at 75 decibels.
  • Choose an adequate duty cycle. Five minutes of continuous shredding can handle about 100 passes. Consider the cool-down time too: 20 to 30 minutes is reasonable but some shredders require 90 minutes.
  • Look for safety features. The Consumer Product Safety Commission recommends that control switches and buttons be raised or printed with high-contrast labels to minimize the risk of hitting the wrong button by accident. Slots should be slim to minimize the chance that a finger will be inserted; separate, thicker slots for credit cards and data discs should have safety covers.
  • Look for safe but wide insertion slots. Owners report that it gets tiresome to use a paper shredder that makes you fold all papers to fit them through a narrow opening. An opening that's just barely wider than 8.5 inches is still inconvenient. Look for a paper slot closer to 9 inches wide. Separate slots for credit cards and data discs add convenience and, in many designs, safety as well.
  • Read the manual. We found many owner-written reviews that reveal that users are inserting items that the shredder simply isn't designed to shred, or trying to use a shredder way beyond its duty cycle in order to clear a backlog of paperwork. Similarly, many users don't realize that their paper shredder requires regular lubrication.
  • Mesh bins can be dusty. It's handy to be able to see how full the waste bin is getting, but owners say translucent bins or bins with windows are cleaner than wire mesh bins, which can allow paper dust to escape.
  • Reverse mode helps clear paper jams. An auto-reverse feature even takes care of this automatically.

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