8331
The 3D printed impact test specimens were examined in order to compare the effect of stress concentrator fabrication on impact test data where two methods were used to fabricate the stress concentrating notch : ( 1 ) printing the stress concentrator ; and ( 2 ) machining the stress concentrator where the dimensions of the notch matched those specified in the ASTM standard D256-10 .
 3D printed, stress, fabrication, impact test, data, fabricate, stress, notch, stress, machining, stress, dimensions, notch, standard
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 3D printed, stress, fabrication, impact test, data, fabricate, stress, notch, stress, machining, stress, dimensions, notch, standard