There are two usages for concrete mixers – agitating and dry mixing (called wet mixing in Japan, hence the name of W spec)

With “Agitating” usage that the customer uses the concrete mixer just for transportation of fresh concrete from the fresh concrete plant to the job site. For example, “EA106-30A” is the mixer specialised for agitating usage.

The other is “Dry mixing” usage that the customer uses the mixer for making fresh concrete in the mixer drum after loading the sand, aggregate, cement and water into the mixer drum. For example, “EA106-30W” is the mixer for the above method.

The rear opening shape of mixer drum is different between “EA106-30A” and “EA106-30W”. 

“W” spec has wider rear opening than “A” spec, so dry mixing capacity is reduced 1cu.m compared with agitating capacity in our specifications.

The reason why “W” spec has wider rear opening, it is easy to load the sand, aggregate and cement into the mixer drum.

If the customer uses “A” spec for dry mixing, loading of dry materials is very hard since the materials might get clogged at the rear hopper due to the small rear opening. 

If customer uses the concrete mixer only for agitating, “A” spec is better since they can load 1cu.m more.