---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-21-004811"
form_type: "8-K"
ticker: "ASYS"
cik: "0000720500"
company_name: "AMTECH SYSTEMS INC"
filed_at: "2021-11-19T23:59:59+00:00"
generated_at: "2026-06-28T06:44:28.383516+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Amtech dismisses auditor MHM, appoints Grant Thornton; reinstates shareholder special meeting right

## Summary
- Dismissed Mayer Hoffman McCann P.C. as auditor effective Nov 17, 2021; no disagreements in prior two fiscal years.
- Appointed Grant Thornton LLP as independent auditor for FY ending Sep 30, 2022, effective Nov 19.
- Board reinstated shareholder right to call special meeting; threshold lowered to 35% of voting shares.

## SEC filing metadata
- accession: 0000950170-21-004811
- form_type: 8-K
- ticker: ASYS
- cik: 0000720500
- company_name: AMTECH SYSTEMS INC
- filed_at: 2021-11-19T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 4.01, 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/720500/000095017021004811/0000950170-21-004811-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/720500/000095017021004811/asys-20211116.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-21-004811
- JSON: https://secwatch.observer/filing/0000950170-21-004811.json
- Plain text: https://secwatch.observer/filing/0000950170-21-004811.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.