Glossary
Running Board Glossary: Rocker Panel, Pinch Weld, Cab Length, Wheel to Wheel, Drop Step
Listings and install sheets use a lot of words nobody explains. This glossary covers the part names, mount points and cab terms you will run into, in plain English, and says where a word is the maker's own name and not a standard.
What's on this page
Start with the word that causes the most returns, and it is not a part. It is the cab name. Truck cab types sorts every maker's names into one table, because the same word can mean a different door layout on a different truck.
A second warning before the list: the product words overlap on purpose. Sellers stack them to catch every search. A single Tyger title can say running board, side step, rail and nerf bars in one line, so those words do not tell you the shape of the part. The width and the shape in the title do. If you want the plain version of what each product is, read what are running boards.
Why the mount words matter
Three of the words below decide how hard your install is: pinch weld, threaded insert and DEF tank. Install sheets split their steps on them. Tyger's sheet for the Ram crew cab Riser, for example, has one procedure for trucks with factory threaded inserts and another for trucks that need a nut plate, and it warns that some models need holes drilled through the pinch weld. How to install running boards walks through the job, and can you install running boards without drilling covers which kits ask for a drill.
Why the length words matter
Cab length and wheel to wheel are the other pair that changes what you buy. Cab-length boards follow the cab. Wheel-to-wheel boards also depend on your bed. Bed and cab fitment has that in detail, and how to check a listing fits turns it into a routine you can run on any listing before you order.
How we use these words
We repeat a maker's or a seller's word the way they use it, and we say whose word it is. We do not treat any of these names as a standard, because we found no standard behind them. Fit on this site is only ever stated the way a listing title or a maker states it, and how we verify fitment explains that rule. Where a definition leans on one source, the source is named in the entry so you can go and check it. Anything here that we could not trace to a maker, a listing or a reference stays a plain description of how the word gets used. Once the words make sense, running boards by truck is the place to start shopping.
- Access Cab
- Toyota's name for an extended-type cab. ARIES lists it on the Tacoma from 2005 and on the Tundra for 2000-2006. Newer Tacoma listings say XtraCab.
- Backsplash
- A plastic strip that fits along a board. LUVERNE sells backsplash kits for some of its boards and describes them as adding a finished look.
- Bed length (box length)
- How long the pickup bed is. Ford calls it the box. It matters for wheel-to-wheel boards and any part that runs past the cab. Cab-length listings we read name no bed at all.
- Bed step
- A step at the side of the pickup bed, so you can reach over the rail or climb in without dropping the tailgate. AMP's BedStep2 deploys with a press of your foot, and RealTruck says to keep it stowed when driving.
- Body mount
- A bracket fixed to the side of the body panel. LUVERNE's application guide marks each kit as Body or Rocker mount, so one truck can have more than one bracket set.
- Breakover angle
- How sharp a crest a truck can clear before its belly touches, measured around the midpoint of the wheelbase. Ford publishes it as ramp breakover angle on its F-150 sheet.
- Cab length
- A board that runs along the cab only. ARIES says these typically give easier access to the cab and usually cost less than wheel-to-wheel boards.
- Chassis cab
- A truck sold as a cab and frame without a pickup bed. Westin's Pro-e footnotes exclude chassis cabs with a DEF tank, so a pickup listing does not automatically cover one.
- Clip nut
- A nut on a spring clip that slides over a tab or hole. Tyger's TG-SS2C35018 sheet uses them over the flat tabs on the pinch weld to give a bolt something to thread into.
- Crew cab
- The largest of the three cab groups in the ARIES guide, typically with four full-size, front-hinging doors and two full rows.
- CrewMax
- Toyota's crew-group cab on the Tundra from 2007. A separate listing from the Tundra Double Cab.
- DEF tank
- The diesel exhaust fluid tank. It can sit close to the body where a bracket goes. Tyger's TG-SS2C35018 sheet says models with one may require cutting, and tells you how to reach the mount.
- Double Cab
- A maker's name with no single meaning. ARIES files the Silverado, Sierra and 2007-to-current Tundra Double under extended, and the Tacoma Double under crew. Check your own rear doors.
- Drop step
- A rail whose step sits lower than the rail itself, so the first step is shorter. It trades room under the step for an easier climb.
- Extended cab
- A cab with at least two full-size front doors and seating behind the first row, reached by moving the front seats or through smaller rear doors, per ARIES.
- Factory stud
- A threaded post already on the truck at a mounting location. Some Tyger sheets bolt brackets straight to these, and one says to clear paint or undercoating from them first.
- Factory threaded insert
- A threaded hole already in the body panel, often behind a plastic plug. Tyger's sheets split their steps by whether your truck has these or needs a nut plate instead.
- Footboard
- An older word for a running board. Wikipedia treats the two as the same thing.
- Ground clearance
- The distance from flat ground to the lowest part of the vehicle, typically the bottom of the differential housing. A step can cut the room under the side of the truck without changing this figure.
- Hitch step
- A step that goes in the hitch receiver at the rear of the truck. It helps at the tailgate and does nothing for the cab.
- Hoop step
- A single short step for one door, usually sold as a pair, instead of one long board or tube.
- LD / Limited
- A label on some 2019 GM trucks. Several listing titles group the 2019 Silverado LD or Sierra Limited with the 2007-2018 trucks or exclude it from 2019-up parts. Our source is listings only, not a GM document.
- Linkage
- The arms that swing a power step out and back. Motors drive them, and RealTruck's guide says mud, dirt or salt caught there can make noise.
- Load rating
- The weight a maker says a step can carry. No shared standard exists for pickup steps, so check whether the figure is per side or for the pair. On this site only a maker document for that exact part counts.
- Mega Cab
- Ram's name for a large cab on the 2500 and 3500, which ARIES files in the crew group alongside the Crew Cab.
- Nerf bar
- Usually a step tube. The word is not a build guarantee: Tyger's TG-SS2C35068 title uses running boards, side step, rail and nerf bars at once. Go by shape and width in the title.
- New body
- The name listing titles use for the Ram 1500 redesigned for 2019, as opposed to the Classic. A title for one often rules out the other, so check which you own.
- Nut plate (bolt plate)
- A plate with a welded nut that you feed into a hole in the body panel, on trucks with no threaded insert. Tyger's TG-RS2D40078 sheet has a plastic retainer to stop it falling inside.
- OBD II plug
- The truck's diagnostic port. RealTruck's guide for the AMP PowerStep 76255-01A uses a plug at this port as part of the install.
- Pinch weld
- The welded seam along the bottom edge of the body. Tyger's sheets mount brackets here, and some sheets say a truck without factory holes needs drilling through it.
- Power step
- A motorized step that deploys when a door opens and stows when the doors close. Also sold as a power running board. RealTruck's AMP guide states a 2-second delay before it stows.
- Quad Cab
- Ram's name for its extended-group cab on the 1500, per ARIES. ARIES lists no extended-group cab for the 2500 and 3500, though at least one listing title names both.
- Ram 1500 Classic
- The older-body Ram 1500 sold for 2019-2024 alongside the new body. Listing titles and Westin's table keep the two apart, so the same model year can be either truck.
- Regular cab
- The smallest of the three cab groups: two full-size, front-hinging doors, seats for two or three and usually no space behind the row, per ARIES.
- Rock slider
- Side protection built to take rock contact, rather than a step first. On Amazon, many listings with this phrase in the title are step rails with the term added, so read the title closely.
- Rocker mount
- A bracket fixed at the rocker area below the doors. LUVERNE's application guide marks kits as Rocker or Body, and you need the one that matches your truck's row.
- Rocker panel
- The body section below the base of the door openings, also called a sill. The running board goes below it.
- Running board
- A step mounted below a truck's doors that makes it easier to climb in and out. Each one is built for specific model years and cabs, and sometimes bed lengths.
- Self-tapping screw
- A screw that cuts its own thread. LUVERNE says O-Mega II step pads attach with these, which lets you place the pads where you want them.
- Side step
- A loose term used for nearly any step mounted under the doors. It says nothing certain about shape or width.
- Skill level
- A rating printed in AMP's install guides, on a scale that runs to 4. Level 4 is labeled Experienced, and the guides we read at that level recommend professional installation.
- Static load
- A load that is not moving. ARIES uses the word for its ActionTrac rating. Coming down hard on a step is not a static load, and no document we read gives a figure for that.
- Step bar
- Usually a tube-style step. Ford and Amazon listings both use the word.
- Step pad
- The textured section you stand on, fixed to a tube or board. Some boards have open treads instead, which LUVERNE says knock dirt and snow off boots.
- SuperCab
- Ford's extended-group cab, on the F-150, Super Duty and Ranger, per ARIES. Its boards and SuperCrew boards are listed separately.
- SuperCrew
- Ford's crew-group cab on the F-150 and Ranger. On the Super Duty, Ford's crew-group cab is called Crew Cab.
- Tire step
- A step that hangs on a front tire and comes off afterward. It gets you up to the engine bay or the roof, not into the cab.
- Wheel to wheel
- A board that runs from the front wheel to the rear wheel, across the cab and bed. ARIES says it gives more coverage and typically costs more. Bed length has to match.
- Wire tap
- A clip that joins a new wire to a factory wire without cutting it. RealTruck's AMP guide and WOLFBOX's sheets both use them, so a power step can mean working in the truck's wiring.
- XtraCab
- Toyota's extended-type Tacoma cab name, listed by ARIES for 1995-2004 and used again in newer listings for 2024-up trucks.
Tailgate questions
What is the difference between a rocker panel and a pinch weld?
The rocker panel is the body section below the door openings. The pinch weld is the welded seam along the bottom edge of the body. Tyger's install sheets mount brackets at both, and some warn that a truck without factory holes needs drilling through the pinch weld.
Is a nerf bar the same as a running board?
The words overlap. A nerf bar is usually a step tube and a running board is usually flatter, but listing titles stack both words on one part. Tyger's TG-SS2C35068 title uses running boards, side step, rail and nerf bars at once, so go by the shape and width in the title.
What is the difference between cab length and wheel to wheel?
Per ARIES, cab-length boards run along the cab, and wheel-to-wheel boards run from the front wheel to the rear wheel across the cab and bed. Wheel-to-wheel gives more coverage and typically costs more, and your bed length has to match the part.
Where this comes from
Keep reading
- ExplainerWhat are running boardsA running board is a step mounted below a truck's doors. What running boards are for, what the steps on a truck are called, the types, and how they mount.
- ExplainerTruck cab typesThere are three truck cab types: regular, extended and crew. Each maker names them differently. See Ford, Ram, GM, Toyota and Nissan names, sizes and door layouts.
- ExplainerCab and bed fitmentCab length running boards run along the cab, wheel-to-wheel boards run to the rear wheel. How cab names and bed length decide fit, and how to read a listing title.
- How-toCheck a listing fitsCheck any running board listing against your truck in seven steps: year, cab, exclusions, part number and maker sheet. Real title traps, and what to ask the seller.
- About usHow we verify fitFit here is what a listing title or maker sheet states, marked as such. What we read, what blocked us and why you still confirm year and cab before you buy.
Who writes this
runningboardsfortrucks.com Editorial Team
Fitment, buying advice and explainers
We are the editorial team at runningboardsfortrucks.com. We read listing titles, maker pages and instruction sheets, then write down which truck, year and cab each one states and where we read it. We do not run lab tests and we do not own a test fleet, and we say so openly.
- Fit quoted from the listing or maker
- Sources and dates on every page
- No lab tests, stated openly
- Publisher details in the imprint