April is National Welding Month, a time dedicated to highlighting accomplishments in this important field. At NIST in the 1960s, Ralph Orwick of the NIST Instrument Shops was challenged to build laboratory equipment that could withstand ultrahigh vacuum. To do so, he developed a new welding technique that allowed the welding of previously “unweldable” combinations of high-strength metals, including: stainless steel to stainless steel, inconel, monel, and kovar; inconel to inconel; monel to monel; and titanium to titanium.