1940
In general , manufacturing imperfections might affect thin features more than thick features , hence thin struts should be thickened or well-designed with sufficient safety margin .
 concept or principle: manufacturing imperfections; machine or equipment: struts; material: be; concept or principle: safety
Please list all entity words in the text that fit the category.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} 
Answer:
 concept or principle: manufacturing imperfections; machine or equipment: struts; material: be; concept or principle: safety