Sand blaster in my opinion cuts small round marks (6)

'sand blaster' is the definition.
The definition suggests a singular noun which matches the answer.

'in my opinion cuts small round marks' is the wordplay.
'in my opinion' becomes 'imo' (common abbreviation).
'cuts' indicates putting letters inside (some letters cut their way into other letters).
'small' becomes 's' (abbreviation - e.g. clothes size).
'round' becomes 'o' (round can mean a round object).
'marks' becomes 'M' (former German currency).
's'+'o'='so'
'imo' going within 'so' is 'simoo'.
'simoo'+'m'='SIMOOM'

Can you help me to learn more?