2172
Initially , during the pre-sintering at 1150 °C , evidences of neck formation between the 420 stainless steel particles were observed .
 manufacturing process: pre-sintering; material: 420 stainless steel
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: pre-sintering, 420 stainless steel 
Answer:
 manufacturing process: pre-sintering; material: 420 stainless steel