MECCANIXITY Thread Reducing Nuts Insert M10 x 1mm Male to M6 x 1mm Fine Thread Female Adapters 10mm Long Pipe Fitting Conversion Sleeve Reducer, Pack of 5: Amazon.com: Industrial & Scientific
ViaBlue™ Stainless steel threaded adapter M6/M10 - set of 4 | dienadel.de
Amazon.com: Fitting Reducer Metric M10 M10X1 Female to M6 M6X1 Male Gauge Adapter : Automotive