Working Iron / Manufacturer spotlight
Your material. Your routes. Your next trailer. Explore the SX3 through SX6 and choose a configuration around the work you need to do.
The number identifies the trailer axle count: SX3 has three, SX4 four, SX5 five and SX6 six. Frame length, tub size and lift/steer options complete the picture.
SmithCo specializes in side-dump trailers, with SX models among its wider range. Here, we focus on four families represented in Working Iron’s listings.
Read the full model comparison →The SX lineup
Compare these listed examples. Dimensions and installed equipment vary within each model family; these are not universal specifications.
Start with a three-axle configuration and compare its length with the access and turning space on your jobs.
The featured listing describes a 42-foot frame, 34-foot tub and third lift axle. Other SX3 lengths and equipment packages exist.
View the SX3-42-34 listing →Compare the four-axle layout, frame length and lift/steer equipment against the routes you actually run.
The featured listing describes a 49-foot frame and 36-foot tub, with a first lift axle and fourth steerable/liftable axle.
View the SX4-49-36 listing →
Look closely at axle placement as well as axle count. SmithCo describes a forward liftable/steerable axle behind the landing legs.
The featured listing describes a 49-foot frame, 38-foot tub and first and fifth liftable/steerable axles.
View the SX5-49-38 listing →
SmithCo describes the six-axle model with three fixed axles and three steerable lift axles. Assess the complete truck-and-trailer combination.
The featured listing describes a 53-foot frame, 40-foot tub and lifts at the first, second and sixth axles.
View the SX6-53-40 listing →Before you request a quote
Tell us what you haul, where you operate, your tractor setup and any access constraints. Include a listing link or the models you are comparing.
The complete combination determines fit. Axle count and tub volume alone do not establish legal payload. Confirm the proposed configuration for your routes with the manufacturer or a qualified transport professional.
Use the model guide for the SmithCo lineup and the buying checklist for the questions to put in your quote.
Explore listed configurations and request a quote from the trailer page. Confirm current price, availability, location and included equipment.
Model-family information: SmithCo’s SX Series and individual model pages. Example configurations and photographs: the linked Working Iron listings. Reviewed September 22, 2026. Photographs illustrate listed configurations; manufacturer specifications and individual builds can differ. SmithCo is a trademark of its owner; this resource does not claim manufacturer endorsement.
SmithCo SX Series reference ↗