Precision ratchet
Each click adds exactly 1/16″ of conductor. Count the clicks, or just go by feel like everyone else.
NEW 2026 MODEL
Tools › Pulling & Tensioning › Wire Stretchers
WS-850 Wire Stretcher
Run came up six inches short? Don't pull new wire. Stretch it.
4.9 (12,467 reviews)
$24999
$389.00
Ask your management about crew pricing
Limited stock. Most units are already in someone's van.
- Stretches up to 18% per pass
- No splices. No new pull. No paperwork.
- Lifetime warranty (yours, not the tool's)
18%max stretch per pass
4,800 lbrated pull (please don't)
0splices required
41 yrsof sending apprentices to the van
Why pros keep one in the van
Measure once. Cut once. Stretch as needed.
Gauge conversion
Stretch a spool of 12 AWG down to 14 AWG and pocket the difference. That's free wire.
Category upgrade
Tightens the twists on Cat5e until it's basically Cat6. Cat6A mode available on the Master model.
HDMI extension
Adds up to 3 ft to any HDMI cable. 4K content may arrive slightly later at the far end.
Anti-recoil lock
Holds your stretch while you terminate. Wire stays stretched for up to 30 years, or one inspection, whichever comes first.
Reverse mode
Run came out too long? Flip the selector and the WS-850 compresses it. Great for service loops you regret.
How it works
Three steps. No new pull.
- ClampLock both jaws onto the conductor. Leave at least 4″ between them so the copper has room to think about it.
- CrankWork the ratchet until the gauge reads the length you wish you'd measured in the first place.
- TerminateLand it quickly, before the wire notices. Close the box. Tell no one.
Specifications
Built for the field. Stored in the van.
Every WS-850 is hand-calibrated in our Ohio facility by a technician who has been asked to go get one at least twice.
| Stretch capacity | 5% / 12% / 18% (Apprentice / Journeyman / Master) |
|---|---|
| Compatible conductors | Copper, aluminum, CCA, Cat5e–Cat6A, RG6, HDMI, speaker wire, extension cords, garden hose (unofficially) |
| Fiber | Single-mode only. Multimode gets confused about which way to go. |
| Rated pull | 4,800 lb |
| Weight | 11.2 lb (heavier when you're the one carrying it back) |
| Housing | Aircraft-grade aluminum, reclaimed from an actual aircraft |
| Power | Elbow grease. Master model: 20V cordless (batteries sold separately) |
| Listings | UL* · NEC Art. 310.WS (pending since 1985) |
| Storage location | BACK OF THE VAN · SECOND SHELF · BEHIND THE FISH TAPE |
*Unlisted Laboratories.
Choose your model
A stretcher for every stage of your career.
Apprentice
$12999
- Manual crank
- Up to 5% stretch
- Comes with a laminated card that says "ask your journeyman"
- Not actually for apprentices
Journeyman
$24999
- Ratcheting drive, 36 clicks
- Up to 12% stretch
- Reverse / compress mode
- Always in the other van
Master
$64999
- 20V cordless, brushless
- Up to 18% stretch, Cat6A mode
- Bluetooth app that tells you it's fine
- Sold only to people who already know better
Reviews
Trusted on job sites since before you were born.
★★★★★
"Pulled 300 feet of 4/0 and came up a foot short. Two minutes with the WS-850 and it landed perfectly. Inspector didn't say a word. Mostly because he was laughing."
★★★★★
"Sent my new guy out to get it. He was gone forty-five minutes. Came back with a coffee, a hose clamp, and a newfound respect for the trade. Worth every penny."
★★★★★
"Works great on Cat6. Tried it on fiber and now the light arrives a little tired. Minus one star, still recommend."
★★★★★
"Bought one in 1987. Still haven't found it. Best tool I own."
★★★★★
"Our apprentice looked in every van, the shop, and the supply house. Supply house guy said they were on backorder. That's customer service."
★★★★★
"Journeyman told me to go get it from the van. It was not in the van. Checked twice. Two stars until someone tells me where it actually is."
Support
Frequently asked questions
Is stretched wire code compliant?
The WS-850 is fully compliant with NEC Article 310.WS, which has been "in committee" since 1985. Consult your local AHJ, who will almost certainly want to see it in person.
Does stretching reduce ampacity?
Slightly. But it also increases length, so on average it works out. Our engineers call this "the stretch dividend."
Can I stretch fiber optic cable?
Single-mode, yes. Multimode fibers tend to get confused about which way to go. Never stretch fiber while it's lit. The light falls out.
Will it make my HDMI cable 8K?
No. Stretching adds length, not K. For more K, see our upcoming product line.
My journeyman says there's one in the van. I can't find it.
Very common. Check the second shelf, behind the fish tape. If it's not there, check under the seat, then the other van, then the shop. If you still can't find it, the last person who used it probably left it in the other other van.
Can I stretch a board that was cut too short?
That's a board stretcher, which is a different tool, sold by a different company, to a different trade. Please don't bring that up on our job site.
Do you ship to job sites?
We only ship to vans. If you do not have a van, one will be assigned to you.
Frequently borrowed together
Complete the kit.
BackorderedLeft-Handed ScrewdriverClockwise-reversed, ambidextrous grip
BackorderedBox of Spare OhmsAssorted values, 100 ct
BackorderedCan of Striped PaintRed/white, 1 qt
BackorderedBucket of SteamFor conduit bending, 5 gal
BackorderedSky HookRated 500 lb, no anchor needed
BackorderedSpool of Wireless CableCat6, 1000 ft, weightless