Quick Reference

NEMA Motor Frame Size Chart

Every dimension you need to identify, replace, or specify a NEMA-frame electric motor — from the original 42-66 frames through the latest T-frame standards. Search any frame, decode the letter suffixes, and shop matching motors from the brands you trust.

Foundations

Understanding NEMA Motor Frame Sizes

NEMA (National Electrical Manufacturers Association) standardizes the physical dimensions of AC and DC motors so a 56C motor from one manufacturer drops in where another's 56C used to live. The frame number defines mounting bolt locations, shaft diameter, and overall envelope — letting you replace, upgrade, or pair a motor with the right coupling, gearbox, or pump end without re-engineering the rest of the system.

Rigid base mount NEMA motor dimension diagram showing C, N, N-W, P, U, XP DIA, F, F, BA and H

Rigid & Resilient Mount

Foot-mounted motors. F and BA set the mounting-bolt hole pattern; U is the shaft diameter.

C-face NEMA motor dimension diagram showing C, AH, BB, N, N-W, AK, BD, P, U and XP DIA

C-Face & D-Flange

Face-mounted motors used for pumps, gearboxes, and direct-coupled drives. AK and BD define the register/bolt-circle.

Decoder

NEMA Letter Designations

The numbers in a frame size identify the physical envelope; the trailing letters tell you what's been modified — mount type, shaft style, or service rating. Hover any code for a refresher.

TT-frame (1964+)Current dimension standard for general-purpose AC motors.

UU-frame (1952–64)Earlier T-frame predecessor. Larger envelope at the same HP.

CC-faceFooted motor with a machined flange for direct mounting.

DD-flangeFlange-mount without feet, typical of vertical pump motors.

HHFooted motor with a longer "F" dimension (extended base).

JJ / JM / JPJet/close-coupled pump shaft and face configurations.

MM / NOil burner mounting flange (mud-pump style).

SSStandard short shaft for direct connection to driven loads.

TSTSShort-shaft variant of the T-frame.

VVVertical mount (V1 thrust, V2 non-thrust, V3 wash-down etc.).

YYSpecial mounting — see manufacturer outline drawing.

ZZNon-standard shaft extension specified by the OEM.

Reference Tables

NEMA Frame Dimensions

All dimensions in inches (1 in = 25.4 mm). Use the tabs to jump between frame series, or type any frame number to filter instantly. Hover a row to highlight that frame's column.

— frames shown

Framedesignation	DShaft height	ECenterline → foot	2FBolt spacing	BAFoot → shaft	N-WShaft length	VShaft to face	UShaft diameter

All values are reference dimensions per the NEMA MG-1 standard. Always verify against the manufacturer's outline drawing before machining a coupling or modifying a base.

Cheat sheet

Inch / Millimeter Conversions

Working in mixed units? The two formulas below cover almost every NEMA-to-IEC conversion you'll run into; the table inside the tool above can also flip every measurement to mm with a single click.

Inches → millimeters

Multiply the inch value by 25.4.

Example: a 145T with a shaft diameter of 7/8 in = 0.875 × 25.4 = 22.23 mm.

Fractional → decimal inch

Divide the numerator by the denominator.

Example: 5/16 = 5 ÷ 16 = 0.3125 in.

NEMA D dimension

D is the height in inches from the bottom of the foot to the centerline of the shaft × 16, the first two digits of the frame number. D = frame[0..1] / 16 × 16.

Example: a 213T frame has D = 5¼ in.

Shop by type

Electric Motors by Category

Found the frame you need? Jump straight to motors that match.

AC Motors

Single-phase and three-phase AC induction motors for general purpose, NEMA Premium, and severe-duty applications.

Shop AC Motors

DC Motors

Variable-speed DC motors for applications that need precise torque control across a wide speed range.

Shop DC Motors

Gearmotors

Motor and gear reducer combined into a single, compact unit — high torque at low speed for conveyors, mixers, and packaging machinery.

Shop Gearmotors

Motor Parts & Accessories

Replacement bearings, fan covers, conduit boxes, mounting bases, brushes, and capacitors — everything except the motor itself.

Shop Parts & Accessories

Shop Motor Parts & Accessories

Shop by brand

Motors by Brand

Cross-reference your existing motor — or upgrade to a NEMA Premium model from any of these brands.

Top sellers

Popular Electric Motors

The motors customers reach for most often. All ship free on orders over $100.

#5049864

Teco-Westinghouse NP0054 MAX-PE NEMA Premium motor

BrandTeco-Westinghouse

ModelNP0054

$498.96Each

Prices may vary — click through for live price

Add to Cart

#227467

Leeson M1135042.00 — 0.25 HP, 62 RPM DC gearmotor (34 NEMA frame)

BrandLeeson

ModelM1135042.00

$735.00Each

Prices may vary — click through for live price

Add to Cart

#2520510

WEG 02512ES3EOW324T-W22 — 25 HP, 1200 RPM three-phase 324T

BrandWEG

Model02512ES3EOW324T-W22

$3,486.22Each

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#221450

Leeson 098000.00 — 0.50 HP, 1750 RPM DC SCR motor (56C frame)

BrandLeeson

Model098000.00

$439.98Each

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#25344

Baldor EM3615T — 5 HP, 1755 RPM 3-phase NEMA Premium Super-E

BrandBaldor

ModelEM3615T

$827.91Each

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#2525297

Leeson 108048.00 — 0.75 HP, 1800 RPM DC motor (56C frame)

BrandLeeson

Model108048.00

$629.12Each

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Add to Cart

FAQ

Frequently Asked Questions

Where can I find an electric motor near me?

MROSupply ships nationwide from regional distribution centers. Browse our electric motor catalog to filter by frame size, HP, and brand, then check the in-stock indicator on each product page.

Can I use a frame chart to cross-reference a motor from another brand?

Yes. NEMA frame standards guarantee the mounting dimensions match across manufacturers — a 145T motor from Baldor will bolt into the same base as a 145T from WEG or Leeson. Performance, efficiency, and accessories may still differ, so confirm voltage, HP, and service factor before swapping.

What do the dimension codes (e.g. "D", "BA", "C") mean?

Each letter refers to a specific physical measurement on the motor. See the diagrams above and the letter designations grid for a full decoder of suffix letters.

How do I know which frame size I need?

Read the motor's nameplate — the frame designation is stamped on it. If the plate is unreadable, measure D (shaft height to the bottom of the foot) and the 2F bolt spacing, then match those numbers to the dimensions table.

Where do I find other types of top NEMA enclosure rating?

NEMA enclosure ratings (TEFC, ODP, XPFC, etc.) describe environmental sealing — not the frame envelope. Filter the AC motor catalog by enclosure type or contact our team for application-specific guidance.

How do I convert fractional inches to decimal or millimeters?

Divide the fraction (e.g. 5/16 = 0.3125), then multiply by 25.4 to get millimeters. The conversions section above has worked examples, and the unit toggle at the top of the dimensions table will switch the entire table to mm.

Still not sure which frame to order?

Our motor experts can cross-reference any existing motor and match HP, RPM, voltage, and frame in minutes — usually before you finish your coffee.

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