Adjustable handles are commonly used where fastening, unfastening, and adjusting becomes difficult because of tight or awkward spaces. Many of our adjustable handle assemblies are available with metric or imperial threads and with steel or stainless steel inserts.he classic element find use in machine construction, tool making and plant construction, heavy-duty applications.Clamping lever is made from high quality alloy and surface is finished by power coating or blackening for durability and rust protection