Glossary
Roll-Up Tonneau Cover Glossary: Terms in Plain English
Technical terms appear in every product description, but they are rarely explained. This glossary translates the most important terms into plain English – sorted alphabetically.
These are the words you meet on listings and in install sheets, in plain English. Each explanation sticks to what a maker's document or title says. Where the word is a trap, the entry says so.
The fit words that cause the most trouble
Three kinds of words decide whether you buy the right cover. Year words, such as Classic, LD and Limited, tell you which body you have, even if the model year says otherwise. Bed words, such as short, standard and long, mean different lengths on different trucks, and even in one maker's brochure. Bed-option words, such as CarbonPro, RamBox, split tailgate, deck rail and track rail, can rule a cover out altogether.
If you take one thing from this page, take this: compare inches, and read the title to the end. Measuring your bed takes a minute. Then go to your truck, where every title is printed in full.
Words for the parts
Parts have many names. One sheet's hook-and-loop strip is what people often call Velcro. A clamp may be called a bracket on a truck with rails. The bulkhead is simply the front wall of the bed. If a sheet uses a word you cannot place, match it against the drawing in that sheet. If that fails, ask the maker with your part number. Answers to common questions are under questions and answers, and our method for all of this is on how we verify fitment.
Words that sound like a promise
Some words on listings sound firmer than they are. "Universal" is the one to distrust most: every cover we read names a truck. "No-drill" comes from makers, and it usually holds, but read your own sheet. "Locking" depends on how the cover and the tailgate work together, as the security answer explains. "Water-resistant" is the honest word, and RealTruck uses it for its own covers. See the leak answer.
"Fits" in a title is the seller's statement, not a guarantee. That is why we print it word for word and put a date next to it. If a word in a title does not appear on this page, ask the seller what it means for your truck.
Two more words come up on truck pages. Styleside and Fleetside mean the straight-sided bed. Short, standard and long are the bed names Chevrolet and Toyota use, and they do not mean the same length on every truck.
- Bed length
- How long the truck's bed is, in feet or inches. Cover titles sell by it. One bed can go by several names, so compare inches.
- Bed rail
- The top of the bed side. Clamps grip it, and a side rail lines up with its inner edge on the Tyger sheets we read.
- Bulkhead
- The front wall of the bed, behind the cab. Tyger's sheets have the side rail slide into a channel at the bulkhead.
- CarbonPro
- A GM bed name that several Silverado and Sierra titles rule out in plain words. Others do not mention it, so ask the seller.
- Clamp
- The part that holds a cover's side rail to the bed rail. Tyger's sheets space clamps evenly, about 6 to 8 inches from the ends of the rail.
- Classic
- The older Ram 1500 body, sold under that name in years when the new body was also sold. Titles treat it as the older body, and their end years differ.
- Crossbar
- A bar that holds up a soft cover's vinyl. Tyger says crossbars must arch upward, or water pools.
- Deck rail
- A rail system along the bed sides of a Toyota truck, with sliding cleats. Each cover type treats it differently, according to RealTruck.
- Drain tube
- A tube that carries water out from a cover's rail. Rough Country's hard roll-up has two, routed into the front of the bed wall.
- Fleetside
- The straight-sided bed style. Styleside is Ford's word for it. Some titles rule out the flared Flareside or Stepside style.
- GVWR
- Gross vehicle weight rating, your truck's limit on total weight. Rough Country's manual tells you not to exceed it.
- Hard roll-up
- A cover made of aluminum slats joined by a rolling hinge, which rolls to the cab.
- Hook-and-loop strip
- The fabric fastener along a soft cover's edge. Tyger's sheet says to press it down after latching.
- LD or Limited
- A 2019 Silverado or Sierra with the older body. Titles keep it apart from the new 2019 body.
- Listing data only
- Our label for a cover where the title is all we could read. It is never our pick.
- Locking clip
- The part of a soft cover that catches on the side rail. Tyger says the gap must be under 1/16 in, or the cover will not lock securely.
- Over-the-rail liner
- A bed liner that laps over the top of the bed side. Tyger's sheets call for small 2 x 4 in holes for the clamps.
- RamBox
- Lidded storage bins built into a Ram's bed sides. Some titles rule them out.
- Soft roll-up
- A cover made of vinyl over crossbars, which rolls to the cab.
- Split tailgate
- Ram's Multi-Function tailgate, which also opens in two halves. Gator's 6 ft 4 in title rules it out.
- Tension plate
- The part of a soft cover that adjusts how tight the vinyl is. Tyger's moves in steps of 1/8 in.
- Tonneau cover
- Any cover that goes over a truck's bed. It can roll, fold or retract.
- Track rail
- A factory rail in Nissan and Toyota beds. Tyger's sheets say these trucks get separate clamp instructions.
- Year block
- The run of model years a cover's title names. It usually follows a body change, but the title decides.
Where to next
- OverviewQuestionsPlain answers on leaks, weight, drilling, snow, security and fit, each taken from maker documents, with the gaps stated. No hands-on claims and no guessing.
- About usHow we verify fitFit here is what a listing title or a maker sheet states, marked as such. What we read, what blocked us, and why you still confirm year and bed before you buy.
- How-toMeasure your bedMeasure your truck bed in one minute: from the front wall to the closed tailgate, along the floor. Then compare inches with the title, because bed names differ.
- Truck fitAll trucksPick your truck, then your years and bed. Every roll-up tonneau cover listed here quotes the fit wording from its listing or the maker's own sheet.
Who is behind this
rolluptonneaucover.com Editorial Team
Truck fit and buying advice
We are the editorial team at rolluptonneaucover.com. We read listing titles, maker install sheets and truck makers' own bed specifications and sort them truck by truck, with sources on every page. Nobody here has bolted these covers to a truck, and nothing was measured in a lab. We say so plainly.
- Listing titles and maker sheets read
- Sources on every page
- No installs and no lab work
- Publisher details in the imprint