Adjustable manhole risers are the safest and most cost-effective devices to raise the manholes or catch basins up to the grade when repaving the streets by lifting new asphalt. Amercast designs a range of risers and manhole cover extension rings to absorb the impact of heavy traffic hitting the top of the manhole’s frame.

You can reduce traffic disruptions during pavement overlays by installing our high-quality risers that fit various grading adjustments. Our mild steel and cast iron manhole risers come with adjustable patterns conforming to municipal specifications and standards. They have the same diameter and depth as the existing frame, so the manhole lid will be flush with the reinforced pavement or roads after positioning.

Strength and Performance

Our range of manhole risers is made from high-grade cast iron and mild steel to offer strength and resilience to your resurfacing projects. The materials are ASTM A-36 steel grade that meets HS-20 standards. The lower and upper sections of riser bars are welded continuously. They are perfect for the 3-piece riser with a joining material of minimum 16-gauge and maximum 12-gauge A-36 steel. There are no stitch welded sections to threaten the riser strength.

We ensure that our cast iron products are free from any gas holes, shrinkage, sand holes, or surface defects to offer smooth assembling and immediate traffic loading. For better performance, we provide dimensional tolerance up to +/- 1/16th inch per foot. We also assure a minimum thickness of ¾” in steel material for the lower riser and 3/8” for the upper riser.

Load Testing

Amercast manhole cover risers are load-tested for maximum strength and durability. We make products that are D.O.T. approved in most states. The testing is done in accordance with the regulations specified by AASHTO M306. It involves testing the products on a calibrated machine. The casting should hold about 40,000 lbs of proof load for one minute without any visible or permanent deformation or cracks. All our products are certified and approved because quality assurance is our top priority.

High-Quality Adjustment Device

For better gripping power, we have integrated an adjustment device made from ¾” 13 U.N.C. solid 304 stainless steel into the manhole risers. It comes with a maximum length of 4 inches without any plated bolts. The adjustment nuts are also C1020-grade cold rolled steel with a minimum outside diameter of 1″, a minimum length of 1 5/8″ and maximum length up to 1 ¾”.
The ergonomic design allows easy gripping when installing or removing the manhole risers. And the product facilitates adjustments of 0”+ or -1/2” in diameter.

Easy Installation

With high-quality standards and proper specifications, we ensure the easy installation of our manhole risers. As compared to installing a new manhole cover, it hardly takes more than five minutes to install a riser. The adjustable riser rings do not require digging or excavation that can disturb the new pavement.
Once you clean the seats and sidewalls of an existing manhole frame, you may place the adjustable risers inside the frame and expand it for a perfect fit using a screwdriver. After installing the riser, put the lid back on it, and your job is done. Since our manhole cover extension rings come with a one-piece assembly, there are no loose parts to handle.

Identifiable Markings

According to the regulatory specifications, we provide every manhole extension ring with our name’s initials, date of manufacture, and a manufacturing plant’s initials.

High-Grade Casting

We use gray iron castings for heavy-duty applications. The castings have a uniform quality with smooth grounding and proper cleaning through the shot blasting method. Every part is skillfully cast and machine with precision to withstand heavy traffic. We follow the cast dimensions within acceptable foundry tolerances. As per regulatory requirements, all our manhole risers, adjustable risers, and manhole cover extension rings are coated with black asphalt paint for extra protection.

Made in America

Our entire range is melted, machined, finished, painted, and assembled exclusively in the U.S.A. We proudly cast ‘Made in the U.S.A.’ marking in compliance with the federal marking laws. Accordingly, the manhole rings and risers have markings on the top surface where you can easily see them after installing. We own a modern facility with world-class machinery, processes, and systems to produce high-quality cast iron products at competitive prices.