On most commercial jobs the metal-stud partition is not a separate framing subcontract. It is the drywall sub’s wall: track, stud, board, and often the insulation and the head-of-wall. Residential shops meet the same members on townhomes, mixed-use, and light commercial that land on an otherwise wood bid list.
This is a field and takeoff briefing, not an engineering stamp. Member selection for height, gauge, and deflection comes from the project documents and the manufacturer’s limiting-height tables. ClarkDietrich, Marino\WARE, and peers publish those tables. Do not guess.
Interior nonstructural studs and their installation are covered in ASTM C645 (members) and ASTM C754 (installation). Structural CFS is a different family (AISI, ASTM C955). If the wall is load-bearing or an exterior wall, it is not “25-ga drywall stud” work.
What the pieces are
C-stud (S): the vertical. Web depth is the wall’s cavity (1-5/8, 2-1/2, 3-5/8, 4, 6 inch are the everyday interiors). Flange width is commonly 1-1/4 inch on drywall studs; structural flanges run wider.
Track (T): U-shaped runner at floor and head. Same web as the stud. Hemmed legs. Floor track gets shot or screwed to slab; head track may be solid or slotted deflection track where the deck is expected to move.
EQ / equivalent-gauge studs: lighter mil thickness with rolled geometry that the manufacturer rates as a 25-ga or 20-ga drywall equivalent. They are not a free upgrade to structural 20-ga. Use them only where the spec and the height table allow EQ.
Furring hat channel, resilient channel, Z-furring: for board on masonry, acoustic isolation, or wrapping steel. Fastener length and which flange you hit change; see how to hang drywall.
Shaftwall studs and J-runners: tabbed or CH-style studs and J-track that catch 1-inch shaftliner. This is its own system, not a 3-5/8 drywall stud with thicker board.
Bridging / strapping: keeps studs from twisting until board is on, and stays in the wall when the design is non-composite or the board does not run full height both sides.
Gauge, mils, and the color stickers
The trade still says “25-ga” and “20-ga.” The shop drawing says mils. They are not interchangeable slang.
| Common call | Approx. mils (design) | Typical use on a drywall package |
|---|---|---|
| 25-ga drywall | ~18 mil | Standard interior partitions, modest height |
| 20-ga drywall (20 DW) | ~30 mil | Taller interiors, doors, abuse walls |
| 20-ga structural | ~33 mil | When the spec leaves “drywall” 20-ga and means structural — read it |
| 18-ga | ~43 mil | Tall walls, heavier finishes, some exterior interior-liners |
| 16-ga and heavier | ~54 mil+ | Structural / specialty — usually not a TI partition |
Manufacturers color-code bundles. Learn the chart on the steel you bought this quarter; EQ lines add their own colors. Marino\WARE and ClarkDietrich both publish nomenclature like 362S125-18: 3-5/8 web, stud, 1-1/4 flange, 18 mil.
Lower gauge number = thicker steel in old speak. Higher mils = thicker steel in the drawing. Say mils in the trailer if the tag says mils.
Spacing, height, and deflection
16 inches o.c. is the default that finishers and hanger production assume. 24 inches o.c. is common on interiors when the height table and the gypsum span allow it — and when the finish level can live with a slightly more flexible wall. Critical-light Level 5 and heavy tile or stone are not where you stretch 25-ga to 24 inches because the stud count looked cheap.
Interior partitions still see a 5 psf lateral design load in the code tables even when they are “nonstructural.” Height, stud depth, mils, spacing, yield (33 ksi vs 50 ksi EQ), and whether both faces are boarded (composite vs non-composite) all change the allowable height.
Deflection limits you will see on finish-sensitive walls:
- L/120 — utilitarian, some textured or covered walls
- L/240 — everyday commercial partitions
- L/360 — tile, stone, brittle finishes, many Level 5 corridors
If the interior elevation is Level 5 in grazing light, a wall that meets L/120 can still look like a wave. That callback is the drywall sub’s, not the steel mill’s.
Do not memorize a single “25-ga goes to 10 feet” rule and bid a 14-foot lobby on it. Open the current limiting-height table for the exact member, spacing, deflection, and composite condition.
Layout the way a drywall crew frames it
- Snap tracks. Square to the building grid, not to a drunk corridor paint line.
- Fasten floor track. Leave openings marked for doors.
- Head track: solid where the deck is not moving; slotted deflection track where the structure will live-load. Studs are not welded to a slotted head — they float in the slots so the deck can move without crushing the wall. Gypsum on the face still needs the right head-of-wall fire detail if the wall is rated.
- Studs: cut to the published gap under a deflection head (often on the order of 1/2 inch to 1 inch depending on the track — read the product). Plumb. Square. 16 or 24 as drawn.
- Jacks and headers at doors. Heavy frames and full-height borrowed lites eat 20-ga or boxed studs even when the field is 25-ga. Full-height frames also count as control joints in the gypsum.
- Bridging if the table or the unclad height requires it.
- Knockouts for MEP. Do not torch a 25-ga web into lace and then ask the board to stiffen it.
- Insulation / SAFB if it is in the drywall number — Insulation — before you close the second face.
Shaftwall, area separation, and rated heads
Cavity shaftwall (elevators, stairs, shafts): J-runner at floor, head, and ends; 1-inch liner panels stand in the tabs; shaft studs engage the liner; occupant-side face layers (often two layers of 5/8 Type X or the design’s Type C) close the room side. Installation is one-sided when the shaft is already occupied or inaccessible. Liner is shaftliner, not leftover wallboard.
Area separation walls in multi-family are cousins: liner, solid or cavity, aluminum breakaway clips on the wood-frame side. Those clips are not optional decoration.
Head-of-wall: a rated partition that stops under a steel deck needs a tested joint (fire-spray, mineral wool and sealant, or a manufactured track/gasket system). The metal-stud package and the firestop package argue about who owns it. Put it in the bid clarifications.
Control joints in the gypsum face are still required on long planes. Deflection track is not a substitute for a 30-foot gypsum control joint.
ACT and drywall ceilings
If the shop also sells acoustical ceiling tile, that grid is not CFS wall stud. Different spec, different hanger wires, different movement joints. Drywall-suspension (steel tees that take gypsum) does sit next to this package — control-joint rules for those ceilings are in the control joints guide and the tee manufacturer’s catalog.
Residential shop notes
You will frame steel on:
- Garage-to-house or mixed-use demising walls specified as CFS
- Light commercial TI that came in through a home-builder relationship
- Furred basement or condo walls
24-ga EQ and 25-ga 3-5/8 at 16 inches will feel familiar if you hang wood all week. Door frames, ceiling height over 9’–10′, and anything rated still need the table. Do not toekick a drywall stud like a 2×4; use the right framing screws (Grabber and every steel house sell them) and crimps where the manufacturer allows.
Related directory
Steel stud / framing, ClarkDietrich, Marino\WARE, Manufacturers, Insulation.
FAQ
Is metal stud usually in the drywall sub’s number?
On commercial interiors, yes — walls and often drywall ceilings. Confirm the bid package. Structural CFS and exterior framing are often someone else.
25-ga or 20-ga?
Height, spacing, deflection, openings, and abuse. Short office partitions are often 25-ga or EQ 25. Tall walls, heavy doors, and L/360 finishes move to 20-ga DW or heavier. Use the table.
What does 362S125-30 mean?
3-5/8-inch web, stud, 1-1/4-inch flange, 30 mil. That is a 20-ga drywall-thickness member in most charts.
Do I need bridging if I board both sides?
Composite walls with board both sides full height are stiffer. You still need bridging when the table says so, when board is missing on one side, or when cladding stops short of the unbraced height.
Can I hang residential 1/2-inch board on 24-inch steel?
Only if the gypsum span and the finish allow it. Ceiling board and fire designs are stricter. When in doubt, 16 inches or 5/8.
Is shaftwall just 6-inch stud and Type X?
No. It is a liner-panel system with dedicated studs and J-track. Wrong members fail the UL design.