Industry Leading DurabilityOur plastic signs are made from 55 mils thick, tear-resistant HDPE (High Density Polyethylene) material. Hard Hat Area Sign is perfect for indoors and limited outdoor use. These signs have a 2-year outdoor warranty, but most signs last longer. Our signs are laminated for enhanced performance. You can clean off graffiti and your graphics are protected. Our Danger - Hard Hat Area Bilingual signs are better than comparable styrene signs, which become brittle and break.USAs Oldest Sign ManufacturerFamily owned since 1918, we take immense pride in our signage. Being one of the oldest certainly means we know this business in and out. Our South Dakota factory is the oldest manufacturer of metal signs in the USA. We have been an integral part of safety and convenience our signs have provided over the years.Signs Give a Warning So You Dont Have ToPersonally warning people is not always the right solution. Say it with signs! OSHA Signs are the safest and the most effective medium to reach out to maximum people on your property.