much on references to primary sources . please improve this by adding secondary or tertiary sources . november 2008 learn how and when to remove this template message nihon dempa kogyo co. ltd. or ndk nihon dempa kogyo kabushiki gaisha tyo 6779 is one of the world s largest quartz crystal companies based in shibuya tokyo japan . using its synthetic quartz crystals ndk produces crystal related products such as crystal devices e.g. crystal units crystal oscillators crystal filters and ultrasonic transducers for medical use . in recent years the company has begun to develop frequency synthesizers and low power wireless modules . in 2010 a ndk facility was heavily damaged by an autoclave explosion killing one person and injuring two others . contents 1 history 2 products 3 location summary 4 see also 5 external links 6 references history edit 1948 ndk was established . 1950 started crystal unit production and sales . 1958 succeeded in test production of synthetic quartz crystal . 1959 started crystal filter production . 1960 started crystal oscillator production . 1963 began trading of ndk stock on the otc market . 1979 developed and industrialized surface acoustic wave saw filter . 1990 listed ndk stock on second section of the tokyo stock exchange . 1998 listed on the first section of the tokyo stock exchange . products edit crystal units crystal oscillators spxo tcxo vcxo ocxo crystal filters surface acoustic wave saw devices optical components synthetic quartz crystals ultrasonic transducers frequency synthesizers location summary edit ndk has sales offices in japan china france germany italy malaysia singapore united kingdom and united states . ndk has production and engineering facilities in japan china germany malaysia and the united states . ndk s belvidere il facility was heavily damaged in a 2009 explosion that destroyed one building killed a man at a nearby gas station and injured two others in a nearby office building . the explosion was in a crystal growth autoclave that had undergone stress corrosion cracking and was inadequately inspected ; recommendations from a previous incident were ignored . 1 demolition of the facility began in march 2015 . 2 see also edit ndk crystal inc. external links edit nihon dempa kogyo co. ltd. references edit http www.csb.gov csb finds fatal 2009 ndk explosion resulted from stress corrosion cracking of high pressure vessel crystal maker failed to inspect or test vessels and to heed earlier warning about risk to public http www.wifr.com home headlines final report in ndk explosion to be released 230911101.html retrieved from https en.wikipedia.org w index.php title nihon dempa kogyo & oldid 723468049 categories electronics companieselectronics companies of japanformer defense companies of japanhidden categories articles lacking reliable references from november 2008all articles lacking reliable referencesarticles containing japanese language text navigation menu personal tools not logged intalkcontributionscreate accountlog in namespaces article talk variants views read edit view history more search navigation main pagecontentsfeatured contentcurrent eventsrandom articledonate to wikipediawikipedia store interaction helpabout wikipediacommunity portalrecent changescontact page tools what links hererelated changesupload filespecial pagespermanent linkpage informationwikidata itemcite this page print export create a bookdownload as pdfprintable version languages edit links this page was last modified on 3 june 2016 at 06 14 . text is available under the creative commons attribution sharealike license ; additional terms may apply . by using this site you agree to the terms of use and privacy policy . wikipedia is a registered trademark of the wikimedia foundation inc. a non profit organization . privacy policy about wikipedia disclaimers contact wikipedia developers cookie statement mobile view