7018 welding rod: which one runs on your machine, and how to keep it dry
7018 is a low-hydrogen rod: what H4R and MR mean, which 7018 runs on a small AC welder, and Lincoln, Hobart and ESAB storage and re-dry temperatures.
7018 is the rod most people move to once they can strike an arc, and it is the one rod whose storage the makers take seriously. It is a low-hydrogen rod: the coating is made to keep hydrogen out of the weld, and moisture it absorbs puts hydrogen back in.
Pick the version your machine can run: on a DC inverter any 7018, on a small AC welder a 7018 made for AC, such as Lincoln 7018 AC or Hobart 7018AC. Keep opened rods warm and dry. Lincoln and Hobart publish holding temperatures of 220 to 350 F and a re-dry after long exposure.
Which 7018 runs on your machine
From each maker’s data sheet or product page, checked 2026-09-27:
| Rod | Class | Current as published | Small AC welders |
|---|---|---|---|
| Lincoln Excalibur 7018 MR | E7018 H4R | DC+ preferred, AC | Not stated |
| Lincoln 7018 AC | E7018 H8 | AC preferred, DC+ | Lists low open circuit voltage operation |
| Hobart 7018 (retail) | E7018 | AC or DCEP | “Not for low-voltage AC welders” |
| Hobart 7018AC (retail) | E7018 | AC or DCEP | Sold for 208/230 V AC welders |
| Hobart 18AC (industrial) | E7018 H8 | AC, DCEP or DCEN | Lists farms, hobbyists and shops |
| ESAB Atom Arc 7018 | E7018 H4R | AC, DC+ | Not stated |
| Forney 30805 | E7018 | DCEP or DCEN | Not recommended for low open circuit voltage |
| Forney 30685 | E7018 AC | AC, DCEN, DCEP | Not stated |
| YesWelder E7018 | E7018 | Not published | Not published |
| ARCCAPTAIN E7018 | E7018 | Not published | Not published |
Forney’s 30805 page lists DCEN and no AC, which no other maker lists for E7018. We quote it as published.
Sources: Lincoln 7018 AC and Excalibur 7018 MR data sheets; Hobart 18AC; Hobart retail 7018; Forney 30805.
What H4, R and MR mean
- H4 or H8. The hydrogen ceiling in the weld metal. Lincoln: H4 means a maximum of 4.0 ml per 100 g on the AWS test. Lincoln 7018 AC and Hobart 18AC are H8.
- R. Moisture resistant. Lincoln: the rod meets specific low moisture pickup limits under controlled humidity tests.
- MR. Lincoln’s name for its moisture resistant rods, as in Excalibur 7018 MR.
R does not make storage optional. Lincoln’s words: all low hydrogen stick electrodes should be stored properly, even those with an R suffix.
Storage and re-dry, by maker
| Rod | Opened rods kept at | Re-dry after exposure |
|---|---|---|
| Lincoln low-hydrogen (7018 MR, 7018 AC) | 250 to 300 F cabinet | 650 to 750 F, one hour at temperature |
| Hobart 418 and 18AC | 220 to 350 F oven | One hour at 575 F |
| Hobart 718MC | 250 to 350 F | 500 to 800 F for one to two hours |
| ESAB (general guidance) | 225 to 300 F | Not published for Atom Arc 7018 |
| Forney, YesWelder, ARCCAPTAIN | Not published | Not published |
Lincoln adds two cautions. Rods that are wet should be pre-dried at 180 to 220 F for one to two hours before the full re-dry. And several hours at a lower temperature is not the same as the specified re-dry. If re-drying leaves the coating fragile, flaking or breaking off, Lincoln says to discard the rods.
On exposure, Lincoln says standard 7018 rods should be supplied to welders twice per shift, and moisture resistant types may be out for up to 9 hours. ESAB says any rod exposed to humid air for more than a few hours needs preheating before use.
Sources: Lincoln storing and redrying guide; Hobart 418 and 718MC data sheets; ESAB.
What moisture does
Lincoln describes a scale. Some moisture can cause hydrogen induced cracking, particularly in higher strength steels. More causes porosity that Lincoln says needs x-ray or destructive testing to find. A lot causes visible porosity, runny slag, a rough surface, hard slag removal and cracking. Because the middle stage hides inside the weld, the makers set storage rules rather than telling you to judge by eye.
A practical reading for a home shop: buy a pack size you will use before it sits open for long, and keep the rest sealed.
Buying 7018
These listings matched the maker’s part number when checked on 2026-09-27:
| Rod | Package | Listing |
|---|---|---|
| Hobart 7018, 1/8 in | 10 lb | Hobart 770479 |
| Hobart 7018, 3/32 in | 5 lb | Hobart 770482 |
| Hobart 7018AC, 1/8 in | 10 lb | Hobart 770475 |
| YesWelder E7018, 1/8 in | 10 lb | YesWelder; current and storage Not published |
| ARCCAPTAIN E7018, 1/8 in | 10 lb | ARCCAPTAIN; current and storage Not published |
We found no Lincoln Excalibur 7018 MR listing we could match to a single package, and the Lincoln 7018 AC listings had no buy box. 3/32 inch runs at lower amps than 1/8; check both against your machine in the welding amps chart.
7018 is often sold for structural work. Structural welds, trailers, hitches and anything holding pressure belong to a certified welder. The other rod classes are compared in welding rods.
Frequently asked questions
Do I need a rod oven for 7018?
Every maker we read says to store opened low-hydrogen rods warm: Lincoln in a cabinet at 250 to 300 F, Hobart in an oven at 220 to 350 F. Lincoln adds that all low-hydrogen rods should be stored properly, even those with an R suffix.
What is the difference between 7018 and 7018 AC?
Both are E7018. The AC versions are designed around AC welders: Lincoln 7018 AC lists AC as preferred and low open circuit voltage operation, and Hobart sells its retail 7018AC for 208/230 volt AC welders. Lincoln 7018 AC and Hobart's industrial 18AC are classed H8, not H4.
How long can 7018 sit out of the can?
Lincoln says standard EXX18 rods should be supplied to welders twice per shift, and moisture resistant types may be exposed for up to 9 hours. Codes can set other limits.